drivers/s390/block/dasd_eckd.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *		    Horst Hummel <Horst.Hummel@de.ibm.com>
 *		    Carsten Otte <Cotte@de.ibm.com>
 *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * Copyright IBM Corp. 1999, 2009
 * EMC Symmetrix ioctl Copyright EMC Corporation, 2008
 * Author.........: Nigel Hislop <hislop_nigel@emc.com>
 */

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/hdreg.h>	/* HDIO_GETGEO			    */
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/utsname.h>
#include <linux/io.h>
#include <linux/overflow.h>

#include <asm/css_chars.h>
#include <asm/machine.h>
#include <asm/debug.h>
#include <asm/idals.h>
#include <asm/ebcdic.h>
#include <asm/cio.h>
#include <asm/ccwdev.h>
#include <asm/itcw.h>
#include <asm/schid.h>
#include <asm/chpid.h>

#include "dasd_int.h"
#include "dasd_eckd.h"

/*
 * raw track access always map to 64k in memory
 * so it maps to 16 blocks of 4k per track
 */
#define DASD_RAW_BLOCK_PER_TRACK 16
#define DASD_RAW_BLOCKSIZE 4096
/* 64k are 128 x 512 byte sectors  */
#define DASD_RAW_SECTORS_PER_TRACK 128

MODULE_DESCRIPTION("S/390 DASD ECKD Disks device driver");
MODULE_LICENSE("GPL");

/*
 * Default full-track write bias applied to every ESE volume at online time;
 * individual volumes can be re-tuned afterwards through their per-device
 * full_track_bias sysfs attribute. 0 disables full-track writes, 100 always
 * uses them, 50 (the default) enables the adaptive heuristic. Values above
 * DASD_FT_BIAS_MAX are capped when applied.
 */
static unsigned int full_track_bias = DASD_FT_BIAS_DEFAULT;
module_param(full_track_bias, uint, 0644);
MODULE_PARM_DESC(full_track_bias,
		 "Default ESE full-track write bias 0..100 (0=off, 1..99=adaptive, 100=always)");

static struct dasd_discipline dasd_eckd_discipline;

/* The ccw bus type uses this table to find devices that it sends to
 * dasd_eckd_probe */
static struct ccw_device_id dasd_eckd_ids[] = {
	{ CCW_DEVICE_DEVTYPE (0x3990, 0, 0x3390, 0), .driver_info = 0x1},
	{ CCW_DEVICE_DEVTYPE (0x2105, 0, 0x3390, 0), .driver_info = 0x2},
	{ CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3380, 0), .driver_info = 0x3},
	{ CCW_DEVICE_DEVTYPE (0x3990, 0, 0x3380, 0), .driver_info = 0x4},
	{ CCW_DEVICE_DEVTYPE (0x2105, 0, 0x3380, 0), .driver_info = 0x5},
	{ CCW_DEVICE_DEVTYPE (0x9343, 0, 0x9345, 0), .driver_info = 0x6},
	{ CCW_DEVICE_DEVTYPE (0x2107, 0, 0x3390, 0), .driver_info = 0x7},
	{ CCW_DEVICE_DEVTYPE (0x2107, 0, 0x3380, 0), .driver_info = 0x8},
	{ CCW_DEVICE_DEVTYPE (0x1750, 0, 0x3390, 0), .driver_info = 0x9},
	{ CCW_DEVICE_DEVTYPE (0x1750, 0, 0x3380, 0), .driver_info = 0xa},
	{ /* end of list */ },
};

MODULE_DEVICE_TABLE(ccw, dasd_eckd_ids);

static struct ccw_driver dasd_eckd_driver; /* see below */

static void *rawpadpage;

#define INIT_CQR_OK 0
#define INIT_CQR_UNFORMATTED 1
#define INIT_CQR_ERROR 2

/* emergency request for reserve/release */
static struct {
	struct dasd_ccw_req cqr;
	struct ccw1 ccw;
	char data[32];
} *dasd_reserve_req;
static DEFINE_MUTEX(dasd_reserve_mutex);

static struct {
	struct dasd_ccw_req cqr;
	struct ccw1 ccw[2];
	char data[40];
} *dasd_vol_info_req;
static DEFINE_MUTEX(dasd_vol_info_mutex);

struct ext_pool_exhaust_work_data {
	struct work_struct worker;
	struct dasd_device *device;
	struct dasd_device *base;
};

/* definitions for the path verification worker */
struct pe_handler_work_data {
	struct work_struct worker;
	struct dasd_device *device;
	struct dasd_ccw_req cqr;
	struct ccw1 ccw;
	__u8 rcd_buffer[DASD_ECKD_RCD_DATA_SIZE];
	int isglobal;
	__u8 tbvpm;
	__u8 fcsecpm;
};
static struct pe_handler_work_data *pe_handler_worker;
static DEFINE_MUTEX(dasd_pe_handler_mutex);

struct check_attention_work_data {
	struct work_struct worker;
	struct dasd_device *device;
	__u8 lpum;
};

static int dasd_eckd_ext_pool_id(struct dasd_device *);
static int prepare_itcw(struct itcw *, unsigned int, unsigned int, int,
			struct dasd_device *, struct dasd_device *,
			unsigned int, int, unsigned int, unsigned int,
			unsigned int, unsigned int);
static int dasd_eckd_query_pprc_status(struct dasd_device *,
				       struct dasd_pprc_data_sc4 *);
static struct dasd_ccw_req *dasd_eckd_build_cp_tpm_writefulltrack(struct dasd_device *,
								  struct dasd_block *,
								  struct request *,
								  sector_t, sector_t,
								  sector_t, sector_t,
								  unsigned int, unsigned int,
								  unsigned int, unsigned int,
								  struct dasd_ccw_req *);

/* initial attempt at a probe function. this can be simplified once
 * the other detection code is gone */
static int
dasd_eckd_probe (struct ccw_device *cdev)
{
	int ret;

	/* set ECKD specific ccw-device options */
	ret = ccw_device_set_options(cdev, CCWDEV_ALLOW_FORCE |
				     CCWDEV_DO_PATHGROUP | CCWDEV_DO_MULTIPATH);
	if (ret) {
		DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s",
				"dasd_eckd_probe: could not set "
				"ccw-device options");
		return ret;
	}
	ret = dasd_generic_probe(cdev);
	return ret;
}

static int
dasd_eckd_set_online(struct ccw_device *cdev)
{
	return dasd_generic_set_online(cdev, &dasd_eckd_discipline);
}

static const int sizes_trk0[] = { 28, 148, 84 };
#define LABEL_SIZE 140

/* head and record addresses of count_area read in analysis ccw */
static const int count_area_head[] = { 0, 0, 0, 0, 1 };
static const int count_area_rec[] = { 1, 2, 3, 4, 1 };

static inline unsigned int
ceil_quot(unsigned int d1, unsigned int d2)
{
	return (d1 + (d2 - 1)) / d2;
}

static unsigned int
recs_per_track(struct dasd_eckd_characteristics * rdc,
	       unsigned int kl, unsigned int dl)
{
	int dn, kn;

	switch (rdc->dev_type) {
	case 0x3380:
		if (kl)
			return 1499 / (15 + 7 + ceil_quot(kl + 12, 32) +
				       ceil_quot(dl + 12, 32));
		else
			return 1499 / (15 + ceil_quot(dl + 12, 32));
	case 0x3390:
		dn = ceil_quot(dl + 6, 232) + 1;
		if (kl) {
			kn = ceil_quot(kl + 6, 232) + 1;
			return 1729 / (10 + 9 + ceil_quot(kl + 6 * kn, 34) +
				       9 + ceil_quot(dl + 6 * dn, 34));
		} else
			return 1729 / (10 + 9 + ceil_quot(dl + 6 * dn, 34));
	case 0x9345:
		dn = ceil_quot(dl + 6, 232) + 1;
		if (kl) {
			kn = ceil_quot(kl + 6, 232) + 1;
			return 1420 / (18 + 7 + ceil_quot(kl + 6 * kn, 34) +
				       ceil_quot(dl + 6 * dn, 34));
		} else
			return 1420 / (18 + 7 + ceil_quot(dl + 6 * dn, 34));
	}
	return 0;
}

static void set_ch_t(struct ch_t *geo, __u32 cyl, __u8 head)
{
	geo->cyl = (__u16) cyl;
	geo->head = cyl >> DASD_EAV_CYL_HI_SHIFT;
	geo->head <<= DASD_EAV_HEAD_HI_SHIFT;
	geo->head |= head;
}

static void set_chr_t(void *addr, __u32 cyl, __u8 head, __u8 record)
{
	struct chr_t *geo = addr;

	geo->cyl = (__u16)cyl;
	geo->head = cyl >> DASD_EAV_CYL_HI_SHIFT;
	geo->head <<= DASD_EAV_HEAD_HI_SHIFT;
	geo->head |= head;
	geo->record = record;
}

/*
 * calculate failing track from sense data depending if
 * it is an EAV device or not
 */
static int dasd_eckd_track_from_irb(struct irb *irb, struct dasd_device *device,
				    sector_t *track)
{
	struct dasd_eckd_private *private = device->private;
	u8 *sense = NULL;
	u32 cyl;
	u8 head;

	sense = dasd_get_sense(irb);
	if (!sense) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			      "ESE error no sense data\n");
		return -EINVAL;
	}
	if (!(sense[27] & DASD_SENSE_BIT_2)) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			      "ESE error no valid track data\n");
		return -EINVAL;
	}

	if (sense[27] & DASD_SENSE_BIT_3) {
		/* enhanced addressing */
		cyl = sense[30] << 20;
		cyl |= (sense[31] & 0xF0) << 12;
		cyl |= sense[28] << 8;
		cyl |= sense[29];
	} else {
		cyl = sense[29] << 8;
		cyl |= sense[30];
	}
	head = sense[31] & 0x0F;
	*track = cyl * private->rdc_data.trk_per_cyl + head;
	return 0;
}

static int set_timestamp(struct ccw1 *ccw, struct DE_eckd_data *data,
		     struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	int rc;

	rc = get_phys_clock(&data->ep_sys_time);
	/*
	 * Ignore return code if XRC is not supported or
	 * sync clock is switched off
	 */
	if ((rc && !private->rdc_data.facilities.XRC_supported) ||
	    rc == -EOPNOTSUPP || rc == -EACCES)
		return 0;

	/* switch on System Time Stamp - needed for XRC Support */
	data->ga_extended |= 0x08; /* switch on 'Time Stamp Valid'   */
	data->ga_extended |= 0x02; /* switch on 'Extended Parameter' */

	if (ccw) {
		ccw->count = sizeof(struct DE_eckd_data);
		ccw->flags |= CCW_FLAG_SLI;
	}

	return rc;
}

static int
define_extent(struct ccw1 *ccw, struct DE_eckd_data *data, unsigned int trk,
	      unsigned int totrk, int cmd, struct dasd_device *device,
	      int blksize)
{
	struct dasd_eckd_private *private = device->private;
	u16 heads, beghead, endhead;
	u32 begcyl, endcyl;
	int rc = 0;

	if (ccw) {
		ccw->cmd_code = DASD_ECKD_CCW_DEFINE_EXTENT;
		ccw->flags = 0;
		ccw->count = 16;
		ccw->cda = virt_to_dma32(data);
	}

	memset(data, 0, sizeof(struct DE_eckd_data));
	switch (cmd) {
	case DASD_ECKD_CCW_READ_HOME_ADDRESS:
	case DASD_ECKD_CCW_READ_RECORD_ZERO:
	case DASD_ECKD_CCW_READ:
	case DASD_ECKD_CCW_READ_MT:
	case DASD_ECKD_CCW_READ_CKD:
	case DASD_ECKD_CCW_READ_CKD_MT:
	case DASD_ECKD_CCW_READ_KD:
	case DASD_ECKD_CCW_READ_KD_MT:
		data->mask.perm = 0x1;
		data->attributes.operation = private->attrib.operation;
		break;
	case DASD_ECKD_CCW_READ_COUNT:
		data->mask.perm = 0x1;
		data->attributes.operation = DASD_BYPASS_CACHE;
		break;
	case DASD_ECKD_CCW_READ_TRACK:
	case DASD_ECKD_CCW_READ_TRACK_DATA:
		data->mask.perm = 0x1;
		data->attributes.operation = private->attrib.operation;
		data->blk_size = 0;
		break;
	case DASD_ECKD_CCW_WRITE:
	case DASD_ECKD_CCW_WRITE_MT:
	case DASD_ECKD_CCW_WRITE_KD:
	case DASD_ECKD_CCW_WRITE_KD_MT:
		data->mask.perm = 0x02;
		data->attributes.operation = private->attrib.operation;
		rc = set_timestamp(ccw, data, device);
		break;
	case DASD_ECKD_CCW_WRITE_CKD:
	case DASD_ECKD_CCW_WRITE_CKD_MT:
		data->attributes.operation = DASD_BYPASS_CACHE;
		rc = set_timestamp(ccw, data, device);
		break;
	case DASD_ECKD_CCW_ERASE:
	case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
	case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
		data->mask.perm = 0x3;
		data->mask.auth = 0x1;
		data->attributes.operation = DASD_BYPASS_CACHE;
		rc = set_timestamp(ccw, data, device);
		break;
	case DASD_ECKD_CCW_WRITE_FULL_TRACK:
		data->mask.perm = 0x03;
		data->attributes.operation = private->attrib.operation;
		data->blk_size = 0;
		break;
	case DASD_ECKD_CCW_WRITE_TRACK_DATA:
		data->mask.perm = 0x02;
		data->attributes.operation = private->attrib.operation;
		data->blk_size = blksize;
		rc = set_timestamp(ccw, data, device);
		break;
	default:
		dev_err(&device->cdev->dev,
			"0x%x is not a known command\n", cmd);
		break;
	}

	data->attributes.mode = 0x3;	/* ECKD */

	if ((private->rdc_data.cu_type == 0x2105 ||
	     private->rdc_data.cu_type == 0x2107 ||
	     private->rdc_data.cu_type == 0x1750)
	    && !(private->uses_cdl && trk < 2))
		data->ga_extended |= 0x40; /* Regular Data Format Mode */

	heads = private->rdc_data.trk_per_cyl;
	begcyl = trk / heads;
	beghead = trk % heads;
	endcyl = totrk / heads;
	endhead = totrk % heads;

	/* check for sequential prestage - enhance cylinder range */
	if (data->attributes.operation == DASD_SEQ_PRESTAGE ||
	    data->attributes.operation == DASD_SEQ_ACCESS) {

		if (endcyl + private->attrib.nr_cyl < private->real_cyl)
			endcyl += private->attrib.nr_cyl;
		else
			endcyl = (private->real_cyl - 1);
	}

	set_ch_t(&data->beg_ext, begcyl, beghead);
	set_ch_t(&data->end_ext, endcyl, endhead);
	return rc;
}


static void locate_record_ext(struct ccw1 *ccw, struct LRE_eckd_data *data,
			      unsigned int trk, unsigned int rec_on_trk,
			      int count, int cmd, struct dasd_device *device,
			      unsigned int reclen, unsigned int tlf)
{
	struct dasd_eckd_private *private = device->private;
	int sector;
	int dn, d;

	if (ccw) {
		ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD_EXT;
		ccw->flags = 0;
		if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK)
			ccw->count = 22;
		else
			ccw->count = 20;
		ccw->cda = virt_to_dma32(data);
	}

	memset(data, 0, sizeof(*data));
	sector = 0;
	if (rec_on_trk) {
		switch (private->rdc_data.dev_type) {
		case 0x3390:
			dn = ceil_quot(reclen + 6, 232);
			d = 9 + ceil_quot(reclen + 6 * (dn + 1), 34);
			sector = (49 + (rec_on_trk - 1) * (10 + d)) / 8;
			break;
		case 0x3380:
			d = 7 + ceil_quot(reclen + 12, 32);
			sector = (39 + (rec_on_trk - 1) * (8 + d)) / 7;
			break;
		}
	}
	data->sector = sector;
	/* note: meaning of count depends on the operation
	 *	 for record based I/O it's the number of records, but for
	 *	 track based I/O it's the number of tracks
	 */
	data->count = count;
	switch (cmd) {
	case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
		data->operation.orientation = 0x3;
		data->operation.operation = 0x03;
		break;
	case DASD_ECKD_CCW_READ_HOME_ADDRESS:
		data->operation.orientation = 0x3;
		data->operation.operation = 0x16;
		break;
	case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
		data->operation.orientation = 0x1;
		data->operation.operation = 0x03;
		data->count++;
		break;
	case DASD_ECKD_CCW_READ_RECORD_ZERO:
		data->operation.orientation = 0x3;
		data->operation.operation = 0x16;
		data->count++;
		break;
	case DASD_ECKD_CCW_WRITE:
	case DASD_ECKD_CCW_WRITE_MT:
	case DASD_ECKD_CCW_WRITE_KD:
	case DASD_ECKD_CCW_WRITE_KD_MT:
		data->auxiliary.length_valid = 0x1;
		data->length = reclen;
		data->operation.operation = 0x01;
		break;
	case DASD_ECKD_CCW_WRITE_CKD:
	case DASD_ECKD_CCW_WRITE_CKD_MT:
		data->auxiliary.length_valid = 0x1;
		data->length = reclen;
		data->operation.operation = 0x03;
		break;
	case DASD_ECKD_CCW_WRITE_FULL_TRACK:
		data->operation.orientation = 0x0;
		data->operation.operation = 0x3F;
		data->extended_operation = 0x11;
		data->length = 0;
		data->extended_parameter_length = 0x02;
		if (data->count > 8) {
			data->extended_parameter[0] = 0xFF;
			data->extended_parameter[1] = 0xFF;
			data->extended_parameter[1] <<= (16 - count);
		} else {
			data->extended_parameter[0] = 0xFF;
			data->extended_parameter[0] <<= (8 - count);
			data->extended_parameter[1] = 0x00;
		}
		data->sector = 0xFF;
		break;
	case DASD_ECKD_CCW_WRITE_TRACK_DATA:
		data->auxiliary.length_valid = 0x1;
		data->length = reclen;	/* not tlf, as one might think */
		data->operation.operation = 0x3F;
		data->extended_operation = 0x23;
		break;
	case DASD_ECKD_CCW_READ:
	case DASD_ECKD_CCW_READ_MT:
	case DASD_ECKD_CCW_READ_KD:
	case DASD_ECKD_CCW_READ_KD_MT:
		data->auxiliary.length_valid = 0x1;
		data->length = reclen;
		data->operation.operation = 0x06;
		break;
	case DASD_ECKD_CCW_READ_CKD:
	case DASD_ECKD_CCW_READ_CKD_MT:
		data->auxiliary.length_valid = 0x1;
		data->length = reclen;
		data->operation.operation = 0x16;
		break;
	case DASD_ECKD_CCW_READ_COUNT:
		data->operation.operation = 0x06;
		break;
	case DASD_ECKD_CCW_READ_TRACK:
		data->operation.orientation = 0x1;
		data->operation.operation = 0x0C;
		data->extended_parameter_length = 0;
		data->sector = 0xFF;
		break;
	case DASD_ECKD_CCW_READ_TRACK_DATA:
		data->auxiliary.length_valid = 0x1;
		data->length = tlf;
		data->operation.operation = 0x0C;
		break;
	case DASD_ECKD_CCW_ERASE:
		data->length = reclen;
		data->auxiliary.length_valid = 0x1;
		data->operation.operation = 0x0b;
		break;
	default:
		DBF_DEV_EVENT(DBF_ERR, device,
			    "fill LRE unknown opcode 0x%x", cmd);
		BUG();
	}
	set_ch_t(&data->seek_addr,
		 trk / private->rdc_data.trk_per_cyl,
		 trk % private->rdc_data.trk_per_cyl);
	data->search_arg.cyl = data->seek_addr.cyl;
	data->search_arg.head = data->seek_addr.head;
	data->search_arg.record = rec_on_trk;
}

static int prefix_LRE(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
		      unsigned int trk, unsigned int totrk, int cmd,
		      struct dasd_device *basedev, struct dasd_device *startdev,
		      unsigned int format, unsigned int rec_on_trk, int count,
		      unsigned int blksize, unsigned int tlf)
{
	struct dasd_eckd_private *basepriv, *startpriv;
	struct LRE_eckd_data *lredata;
	struct DE_eckd_data *dedata;
	int rc = 0;

	basepriv = basedev->private;
	startpriv = startdev->private;
	dedata = &pfxdata->define_extent;
	lredata = &pfxdata->locate_record;

	ccw->cmd_code = DASD_ECKD_CCW_PFX;
	ccw->flags = 0;
	if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK) {
		ccw->count = sizeof(*pfxdata) + 2;
		ccw->cda = virt_to_dma32(pfxdata);
		memset(pfxdata, 0, sizeof(*pfxdata) + 2);
	} else {
		ccw->count = sizeof(*pfxdata);
		ccw->cda = virt_to_dma32(pfxdata);
		memset(pfxdata, 0, sizeof(*pfxdata));
	}

	/* prefix data */
	if (format > 1) {
		DBF_DEV_EVENT(DBF_ERR, basedev,
			      "PFX LRE unknown format 0x%x", format);
		BUG();
		return -EINVAL;
	}
	pfxdata->format = format;
	/* cached copies - conf.ned may be freed under us by the reload worker */
	pfxdata->base_address = READ_ONCE(basepriv->ned_ua);
	pfxdata->base_lss = READ_ONCE(basepriv->ned_lss);
	pfxdata->validity.define_extent = 1;

	/* private uid is kept up to date, conf_data may be outdated */
	if (startpriv->uid.type == UA_BASE_PAV_ALIAS)
		pfxdata->validity.verify_base = 1;

	if (startpriv->uid.type == UA_HYPER_PAV_ALIAS) {
		pfxdata->validity.verify_base = 1;
		pfxdata->validity.hyper_pav = 1;
	}

	rc = define_extent(NULL, dedata, trk, totrk, cmd, basedev, blksize);

	/*
	 * For some commands the System Time Stamp is set in the define extent
	 * data when XRC is supported. The validity of the time stamp must be
	 * reflected in the prefix data as well.
	 */
	if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
		pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid'   */

	if (format == 1) {
		locate_record_ext(NULL, lredata, trk, rec_on_trk, count, cmd,
				  basedev, blksize, tlf);
	}

	return rc;
}

static int prefix(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
		  unsigned int trk, unsigned int totrk, int cmd,
		  struct dasd_device *basedev, struct dasd_device *startdev)
{
	return prefix_LRE(ccw, pfxdata, trk, totrk, cmd, basedev, startdev,
			  0, 0, 0, 0, 0);
}

static void
locate_record(struct ccw1 *ccw, struct LO_eckd_data *data, unsigned int trk,
	      unsigned int rec_on_trk, int no_rec, int cmd,
	      struct dasd_device * device, int reclen)
{
	struct dasd_eckd_private *private = device->private;
	int sector;
	int dn, d;

	DBF_DEV_EVENT(DBF_INFO, device,
		  "Locate: trk %d, rec %d, no_rec %d, cmd %d, reclen %d",
		  trk, rec_on_trk, no_rec, cmd, reclen);

	ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD;
	ccw->flags = 0;
	ccw->count = 16;
	ccw->cda = virt_to_dma32(data);

	memset(data, 0, sizeof(struct LO_eckd_data));
	sector = 0;
	if (rec_on_trk) {
		switch (private->rdc_data.dev_type) {
		case 0x3390:
			dn = ceil_quot(reclen + 6, 232);
			d = 9 + ceil_quot(reclen + 6 * (dn + 1), 34);
			sector = (49 + (rec_on_trk - 1) * (10 + d)) / 8;
			break;
		case 0x3380:
			d = 7 + ceil_quot(reclen + 12, 32);
			sector = (39 + (rec_on_trk - 1) * (8 + d)) / 7;
			break;
		}
	}
	data->sector = sector;
	data->count = no_rec;
	switch (cmd) {
	case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
		data->operation.orientation = 0x3;
		data->operation.operation = 0x03;
		break;
	case DASD_ECKD_CCW_READ_HOME_ADDRESS:
		data->operation.orientation = 0x3;
		data->operation.operation = 0x16;
		break;
	case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
		data->operation.orientation = 0x1;
		data->operation.operation = 0x03;
		data->count++;
		break;
	case DASD_ECKD_CCW_READ_RECORD_ZERO:
		data->operation.orientation = 0x3;
		data->operation.operation = 0x16;
		data->count++;
		break;
	case DASD_ECKD_CCW_WRITE:
	case DASD_ECKD_CCW_WRITE_MT:
	case DASD_ECKD_CCW_WRITE_KD:
	case DASD_ECKD_CCW_WRITE_KD_MT:
		data->auxiliary.last_bytes_used = 0x1;
		data->length = reclen;
		data->operation.operation = 0x01;
		break;
	case DASD_ECKD_CCW_WRITE_CKD:
	case DASD_ECKD_CCW_WRITE_CKD_MT:
		data->auxiliary.last_bytes_used = 0x1;
		data->length = reclen;
		data->operation.operation = 0x03;
		break;
	case DASD_ECKD_CCW_READ:
	case DASD_ECKD_CCW_READ_MT:
	case DASD_ECKD_CCW_READ_KD:
	case DASD_ECKD_CCW_READ_KD_MT:
		data->auxiliary.last_bytes_used = 0x1;
		data->length = reclen;
		data->operation.operation = 0x06;
		break;
	case DASD_ECKD_CCW_READ_CKD:
	case DASD_ECKD_CCW_READ_CKD_MT:
		data->auxiliary.last_bytes_used = 0x1;
		data->length = reclen;
		data->operation.operation = 0x16;
		break;
	case DASD_ECKD_CCW_READ_COUNT:
		data->operation.operation = 0x06;
		break;
	case DASD_ECKD_CCW_ERASE:
		data->length = reclen;
		data->auxiliary.last_bytes_used = 0x1;
		data->operation.operation = 0x0b;
		break;
	default:
		DBF_DEV_EVENT(DBF_ERR, device, "unknown locate record "
			      "opcode 0x%x", cmd);
	}
	set_ch_t(&data->seek_addr,
		 trk / private->rdc_data.trk_per_cyl,
		 trk % private->rdc_data.trk_per_cyl);
	data->search_arg.cyl = data->seek_addr.cyl;
	data->search_arg.head = data->seek_addr.head;
	data->search_arg.record = rec_on_trk;
}

/*
 * Returns 1 if the block is one of the special blocks that needs
 * to get read/written with the KD variant of the command.
 * That is DASD_ECKD_READ_KD_MT instead of DASD_ECKD_READ_MT and
 * DASD_ECKD_WRITE_KD_MT instead of DASD_ECKD_WRITE_MT.
 * Luckily the KD variants differ only by one bit (0x08) from the
 * normal variant. So don't wonder about code like:
 * if (dasd_eckd_cdl_special(blk_per_trk, recid))
 *         ccw->cmd_code |= 0x8;
 */
static inline int
dasd_eckd_cdl_special(int blk_per_trk, int recid)
{
	if (recid < 3)
		return 1;
	if (recid < blk_per_trk)
		return 0;
	if (recid < 2 * blk_per_trk)
		return 1;
	return 0;
}

/*
 * Returns the record size for the special blocks of the cdl format.
 * Only returns something useful if dasd_eckd_cdl_special is true
 * for the recid.
 */
static inline int
dasd_eckd_cdl_reclen(int recid)
{
	if (recid < 3)
		return sizes_trk0[recid];
	return LABEL_SIZE;
}
/* create unique id from private structure. */
static void create_uid(struct dasd_conf *conf, struct dasd_uid *uid)
{
	int count;

	memset(uid, 0, sizeof(struct dasd_uid));
	memcpy(uid->vendor, conf->ned->HDA_manufacturer,
	       sizeof(uid->vendor) - 1);
	EBCASC(uid->vendor, sizeof(uid->vendor) - 1);
	memcpy(uid->serial, &conf->ned->serial,
	       sizeof(uid->serial) - 1);
	EBCASC(uid->serial, sizeof(uid->serial) - 1);
	uid->ssid = conf->gneq->subsystemID;
	uid->real_unit_addr = conf->ned->unit_addr;
	if (conf->sneq) {
		uid->type = conf->sneq->sua_flags;
		if (uid->type == UA_BASE_PAV_ALIAS)
			uid->base_unit_addr = conf->sneq->base_unit_addr;
	} else {
		uid->type = UA_BASE_DEVICE;
	}
	if (conf->vdsneq) {
		for (count = 0; count < 16; count++) {
			sprintf(uid->vduit+2*count, "%02x",
				conf->vdsneq->uit[count]);
		}
	}
}

/*
 * Generate device unique id that specifies the physical device.
 */
static int dasd_eckd_generate_uid(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	unsigned long flags;

	if (!private)
		return -ENODEV;
	if (!private->conf.ned || !private->conf.gneq)
		return -ENODEV;
	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
	create_uid(&private->conf, &private->uid);
	/* cache LSS and unit address for the lockless CCW-build path */
	WRITE_ONCE(private->ned_lss, private->conf.ned->ID);
	WRITE_ONCE(private->ned_ua, private->conf.ned->unit_addr);
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
	return 0;
}

static int dasd_eckd_get_uid(struct dasd_device *device, struct dasd_uid *uid)
{
	struct dasd_eckd_private *private = device->private;
	unsigned long flags;

	if (private) {
		spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
		*uid = private->uid;
		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
		return 0;
	}
	return -EINVAL;
}

/*
 * compare device UID with data of a given dasd_eckd_private structure
 * return 0 for match
 */
static int dasd_eckd_compare_path_uid(struct dasd_device *device,
				      struct dasd_conf *path_conf)
{
	struct dasd_uid device_uid;
	struct dasd_uid path_uid;

	create_uid(path_conf, &path_uid);
	dasd_eckd_get_uid(device, &device_uid);

	return memcmp(&device_uid, &path_uid, sizeof(struct dasd_uid));
}

static void dasd_eckd_fill_rcd_cqr(struct dasd_device *device,
				   struct dasd_ccw_req *cqr,
				   __u8 *rcd_buffer,
				   __u8 lpm)
{
	struct ccw1 *ccw;
	/*
	 * buffer has to start with EBCDIC "V1.0" to show
	 * support for virtual device SNEQ
	 */
	rcd_buffer[0] = 0xE5;
	rcd_buffer[1] = 0xF1;
	rcd_buffer[2] = 0x4B;
	rcd_buffer[3] = 0xF0;

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_RCD;
	ccw->flags = 0;
	ccw->cda = virt_to_dma32(rcd_buffer);
	ccw->count = DASD_ECKD_RCD_DATA_SIZE;
	cqr->magic = DASD_ECKD_MAGIC;

	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->expires = 10*HZ;
	cqr->lpm = lpm;
	cqr->retries = 256;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
}

/*
 * Wakeup helper for read_conf
 * if the cqr is not done and needs some error recovery
 * the buffer has to be re-initialized with the EBCDIC "V1.0"
 * to show support for virtual device SNEQ
 */
static void read_conf_cb(struct dasd_ccw_req *cqr, void *data)
{
	struct ccw1 *ccw;
	__u8 *rcd_buffer;

	if (cqr->status !=  DASD_CQR_DONE) {
		ccw = cqr->cpaddr;
		rcd_buffer = dma32_to_virt(ccw->cda);
		memset(rcd_buffer, 0, sizeof(*rcd_buffer));

		rcd_buffer[0] = 0xE5;
		rcd_buffer[1] = 0xF1;
		rcd_buffer[2] = 0x4B;
		rcd_buffer[3] = 0xF0;
	}
	dasd_wakeup_cb(cqr, data);
}

static int dasd_eckd_read_conf_immediately(struct dasd_device *device,
					   struct dasd_ccw_req *cqr,
					   __u8 *rcd_buffer,
					   __u8 lpm)
{
	struct ciw *ciw;
	int rc;
	/*
	 * sanity check: scan for RCD command in extended SenseID data
	 * some devices do not support RCD
	 */
	ciw = ccw_device_get_ciw(device->cdev, CIW_TYPE_RCD);
	if (!ciw || ciw->cmd != DASD_ECKD_CCW_RCD)
		return -EOPNOTSUPP;

	dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buffer, lpm);
	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	set_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags);
	cqr->retries = 5;
	cqr->callback = read_conf_cb;
	rc = dasd_sleep_on_immediatly(cqr);
	return rc;
}

static int dasd_eckd_read_conf_lpm(struct dasd_device *device,
				   void **rcd_buffer,
				   int *rcd_buffer_size, __u8 lpm)
{
	struct ciw *ciw;
	char *rcd_buf = NULL;
	int ret;
	struct dasd_ccw_req *cqr;

	/*
	 * sanity check: scan for RCD command in extended SenseID data
	 * some devices do not support RCD
	 */
	ciw = ccw_device_get_ciw(device->cdev, CIW_TYPE_RCD);
	if (!ciw || ciw->cmd != DASD_ECKD_CCW_RCD) {
		ret = -EOPNOTSUPP;
		goto out_error;
	}
	rcd_buf = kzalloc(DASD_ECKD_RCD_DATA_SIZE, GFP_KERNEL | GFP_DMA);
	if (!rcd_buf) {
		ret = -ENOMEM;
		goto out_error;
	}
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* RCD */,
				   0, /* use rcd_buf as data ara */
				   device, NULL);
	if (IS_ERR(cqr)) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			      "Could not allocate RCD request");
		ret = -ENOMEM;
		goto out_error;
	}
	dasd_eckd_fill_rcd_cqr(device, cqr, rcd_buf, lpm);
	cqr->callback = read_conf_cb;
	ret = dasd_sleep_on(cqr);
	/*
	 * on success we update the user input parms
	 */
	dasd_sfree_request(cqr, cqr->memdev);
	if (ret)
		goto out_error;

	*rcd_buffer_size = DASD_ECKD_RCD_DATA_SIZE;
	*rcd_buffer = rcd_buf;
	return 0;
out_error:
	kfree(rcd_buf);
	*rcd_buffer = NULL;
	*rcd_buffer_size = 0;
	return ret;
}

static int dasd_eckd_identify_conf_parts(struct dasd_conf *conf)
{

	struct dasd_sneq *sneq;
	int i, count;

	conf->ned = NULL;
	conf->sneq = NULL;
	conf->vdsneq = NULL;
	conf->gneq = NULL;
	count = conf->len / sizeof(struct dasd_sneq);
	sneq = (struct dasd_sneq *)conf->data;
	for (i = 0; i < count; ++i) {
		if (sneq->flags.identifier == 1 && sneq->format == 1)
			conf->sneq = sneq;
		else if (sneq->flags.identifier == 1 && sneq->format == 4)
			conf->vdsneq = (struct vd_sneq *)sneq;
		else if (sneq->flags.identifier == 2)
			conf->gneq = (struct dasd_gneq *)sneq;
		else if (sneq->flags.identifier == 3 && sneq->res1 == 1)
			conf->ned = (struct dasd_ned *)sneq;
		sneq++;
	}
	if (!conf->ned || !conf->gneq) {
		conf->ned = NULL;
		conf->sneq = NULL;
		conf->vdsneq = NULL;
		conf->gneq = NULL;
		return -EINVAL;
	}
	return 0;

};

static unsigned char dasd_eckd_path_access(void *conf_data, int conf_len)
{
	struct dasd_gneq *gneq;
	int i, count, found;

	count = conf_len / sizeof(*gneq);
	gneq = (struct dasd_gneq *)conf_data;
	found = 0;
	for (i = 0; i < count; ++i) {
		if (gneq->flags.identifier == 2) {
			found = 1;
			break;
		}
		gneq++;
	}
	if (found)
		return ((char *)gneq)[18] & 0x07;
	else
		return 0;
}

static void dasd_eckd_store_conf_data(struct dasd_device *device,
				      struct dasd_conf_data *conf_data, int chp)
{
	struct dasd_eckd_private *private = device->private;
	struct channel_path_desc_fmt0 *chp_desc;
	struct subchannel_id sch_id;
	void *cdp;

	/*
	 * path handling and read_conf allocate data
	 * free it before replacing the pointer
	 * also replace the old private->conf_data pointer
	 * with the new one if this points to the same data
	 */
	cdp = device->path[chp].conf_data;
	if (private->conf.data == cdp) {
		private->conf.data = (void *)conf_data;
		dasd_eckd_identify_conf_parts(&private->conf);
	}
	ccw_device_get_schid(device->cdev, &sch_id);
	device->path[chp].conf_data = conf_data;
	device->path[chp].cssid = sch_id.cssid;
	device->path[chp].ssid = sch_id.ssid;
	chp_desc = ccw_device_get_chp_desc(device->cdev, chp);
	if (chp_desc)
		device->path[chp].chpid = chp_desc->chpid;
	kfree(chp_desc);
	kfree(cdp);
}

static void dasd_eckd_clear_conf_data(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	int i;

	private->conf.data = NULL;
	private->conf.len = 0;
	for (i = 0; i < 8; i++) {
		kfree(device->path[i].conf_data);
		device->path[i].conf_data = NULL;
		device->path[i].cssid = 0;
		device->path[i].ssid = 0;
		device->path[i].chpid = 0;
		dasd_path_notoper(device, i);
	}
}

static void dasd_eckd_read_fc_security(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	u8 esm_valid;
	u8 esm[8];
	int chp;
	int rc;

	rc = chsc_scud(private->uid.ssid, (u64 *)esm, &esm_valid);
	if (rc) {
		for (chp = 0; chp < 8; chp++)
			device->path[chp].fc_security = 0;
		return;
	}

	for (chp = 0; chp < 8; chp++) {
		if (esm_valid & (0x80 >> chp))
			device->path[chp].fc_security = esm[chp];
		else
			device->path[chp].fc_security = 0;
	}
}

static void dasd_eckd_get_uid_string(struct dasd_conf *conf, char *print_uid)
{
	struct dasd_uid uid;

	create_uid(conf, &uid);
	snprintf(print_uid, DASD_UID_STRLEN, "%s.%s.%04x.%02x%s%s",
		 uid.vendor, uid.serial, uid.ssid, uid.real_unit_addr,
		 uid.vduit[0] ? "." : "", uid.vduit);
}

static int dasd_eckd_check_cabling(struct dasd_device *device,
				   void *conf_data, __u8 lpm)
{
	char print_path_uid[DASD_UID_STRLEN], print_device_uid[DASD_UID_STRLEN];
	struct dasd_eckd_private *private = device->private;
	struct dasd_conf path_conf;

	path_conf.data = conf_data;
	path_conf.len = DASD_ECKD_RCD_DATA_SIZE;
	if (dasd_eckd_identify_conf_parts(&path_conf))
		return 1;

	if (dasd_eckd_compare_path_uid(device, &path_conf)) {
		dasd_eckd_get_uid_string(&path_conf, print_path_uid);
		dasd_eckd_get_uid_string(&private->conf, print_device_uid);
		dev_err(&device->cdev->dev,
			"Not all channel paths lead to the same device, path %02X leads to device %s instead of %s\n",
			lpm, print_path_uid, print_device_uid);
		return 1;
	}

	return 0;
}

static int dasd_eckd_read_conf(struct dasd_device *device)
{
	void *conf_data;
	int conf_len, conf_data_saved;
	int rc, path_err, pos;
	__u8 lpm, opm;
	struct dasd_eckd_private *private;

	private = device->private;
	opm = ccw_device_get_path_mask(device->cdev);
	conf_data_saved = 0;
	path_err = 0;
	/* get configuration data per operational path */
	for (lpm = 0x80; lpm; lpm>>= 1) {
		if (!(lpm & opm))
			continue;
		rc = dasd_eckd_read_conf_lpm(device, &conf_data,
					     &conf_len, lpm);
		if (rc && rc != -EOPNOTSUPP) {	/* -EOPNOTSUPP is ok */
			DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
					"Read configuration data returned "
					"error %d", rc);
			return rc;
		}
		if (conf_data == NULL) {
			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
					"No configuration data "
					"retrieved");
			/* no further analysis possible */
			dasd_path_add_opm(device, opm);
			continue;	/* no error */
		}
		/* save first valid configuration data */
		if (!conf_data_saved) {
			/* initially clear previously stored conf_data */
			dasd_eckd_clear_conf_data(device);
			private->conf.data = conf_data;
			private->conf.len = conf_len;
			if (dasd_eckd_identify_conf_parts(&private->conf)) {
				private->conf.data = NULL;
				private->conf.len = 0;
				kfree(conf_data);
				continue;
			}
			/*
			 * build device UID that other path data
			 * can be compared to it
			 */
			dasd_eckd_generate_uid(device);
			conf_data_saved++;
		} else if (dasd_eckd_check_cabling(device, conf_data, lpm)) {
			dasd_path_add_cablepm(device, lpm);
			path_err = -EINVAL;
			kfree(conf_data);
			continue;
		}

		pos = pathmask_to_pos(lpm);
		dasd_eckd_store_conf_data(device, conf_data, pos);

		switch (dasd_eckd_path_access(conf_data, conf_len)) {
		case 0x02:
			dasd_path_add_nppm(device, lpm);
			break;
		case 0x03:
			dasd_path_add_ppm(device, lpm);
			break;
		}
		if (!dasd_path_get_opm(device)) {
			dasd_path_set_opm(device, lpm);
			dasd_generic_path_operational(device);
		} else {
			dasd_path_add_opm(device, lpm);
		}
	}

	return path_err;
}

static u32 get_fcx_max_data(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	int fcx_in_css, fcx_in_gneq, fcx_in_features;
	unsigned int mdc;
	int tpm;

	if (dasd_nofcx)
		return 0;
	/* is transport mode supported? */
	fcx_in_css = css_general_characteristics.fcx;
	fcx_in_gneq = private->conf.gneq->reserved2[7] & 0x04;
	fcx_in_features = private->features.feature[40] & 0x80;
	tpm = fcx_in_css && fcx_in_gneq && fcx_in_features;

	if (!tpm)
		return 0;

	mdc = ccw_device_get_mdc(device->cdev, 0);
	if (mdc == 0) {
		dev_warn(&device->cdev->dev, "Detecting the maximum supported data size for zHPF requests failed\n");
		return 0;
	} else {
		return (u32)mdc * FCX_MAX_DATA_FACTOR;
	}
}

static int verify_fcx_max_data(struct dasd_device *device, __u8 lpm)
{
	struct dasd_eckd_private *private = device->private;
	unsigned int mdc;
	u32 fcx_max_data;

	if (private->fcx_max_data) {
		mdc = ccw_device_get_mdc(device->cdev, lpm);
		if (mdc == 0) {
			dev_warn(&device->cdev->dev,
				 "Detecting the maximum data size for zHPF "
				 "requests failed (rc=%d) for a new path %x\n",
				 mdc, lpm);
			return mdc;
		}
		fcx_max_data = (u32)mdc * FCX_MAX_DATA_FACTOR;
		if (fcx_max_data < private->fcx_max_data) {
			dev_warn(&device->cdev->dev,
				 "The maximum data size for zHPF requests %u "
				 "on a new path %x is below the active maximum "
				 "%u\n", fcx_max_data, lpm,
				 private->fcx_max_data);
			return -EACCES;
		}
	}
	return 0;
}

static int rebuild_device_uid(struct dasd_device *device,
			      struct pe_handler_work_data *data)
{
	struct dasd_eckd_private *private = device->private;
	__u8 lpm, opm = dasd_path_get_opm(device);
	int rc = -ENODEV;

	for (lpm = 0x80; lpm; lpm >>= 1) {
		if (!(lpm & opm))
			continue;
		memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));
		memset(&data->cqr, 0, sizeof(data->cqr));
		data->cqr.cpaddr = &data->ccw;
		rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
						     data->rcd_buffer,
						     lpm);

		if (rc) {
			if (rc == -EOPNOTSUPP) /* -EOPNOTSUPP is ok */
				continue;
			DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
					"Read configuration data "
					"returned error %d", rc);
			break;
		}
		memcpy(private->conf.data, data->rcd_buffer,
		       DASD_ECKD_RCD_DATA_SIZE);
		if (dasd_eckd_identify_conf_parts(&private->conf)) {
			rc = -ENODEV;
		} else /* first valid path is enough */
			break;
	}

	if (!rc)
		rc = dasd_eckd_generate_uid(device);

	return rc;
}

static void dasd_eckd_path_available_action(struct dasd_device *device,
					    struct pe_handler_work_data *data)
{
	__u8 path_rcd_buf[DASD_ECKD_RCD_DATA_SIZE];
	__u8 lpm, opm, npm, ppm, epm, hpfpm, cablepm;
	struct dasd_conf_data *conf_data;
	char print_uid[DASD_UID_STRLEN];
	struct dasd_conf path_conf;
	unsigned long flags;
	int rc, pos;

	opm = 0;
	npm = 0;
	ppm = 0;
	epm = 0;
	hpfpm = 0;
	cablepm = 0;

	for (lpm = 0x80; lpm; lpm >>= 1) {
		if (!(lpm & data->tbvpm))
			continue;
		memset(&data->rcd_buffer, 0, sizeof(data->rcd_buffer));
		memset(&data->cqr, 0, sizeof(data->cqr));
		data->cqr.cpaddr = &data->ccw;
		rc = dasd_eckd_read_conf_immediately(device, &data->cqr,
						     data->rcd_buffer,
						     lpm);
		if (!rc) {
			switch (dasd_eckd_path_access(data->rcd_buffer,
						      DASD_ECKD_RCD_DATA_SIZE)
				) {
			case 0x02:
				npm |= lpm;
				break;
			case 0x03:
				ppm |= lpm;
				break;
			}
			opm |= lpm;
		} else if (rc == -EOPNOTSUPP) {
			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
					"path verification: No configuration "
					"data retrieved");
			opm |= lpm;
		} else if (rc == -EAGAIN) {
			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
					"path verification: device is stopped,"
					" try again later");
			epm |= lpm;
		} else {
			dev_warn(&device->cdev->dev,
				 "Reading device feature codes failed "
				 "(rc=%d) for new path %x\n", rc, lpm);
			continue;
		}
		if (verify_fcx_max_data(device, lpm)) {
			opm &= ~lpm;
			npm &= ~lpm;
			ppm &= ~lpm;
			hpfpm |= lpm;
			continue;
		}

		/*
		 * save conf_data for comparison after
		 * rebuild_device_uid may have changed
		 * the original data
		 */
		memcpy(&path_rcd_buf, data->rcd_buffer,
		       DASD_ECKD_RCD_DATA_SIZE);
		path_conf.data = (void *)&path_rcd_buf;
		path_conf.len = DASD_ECKD_RCD_DATA_SIZE;
		if (dasd_eckd_identify_conf_parts(&path_conf)) {
			path_conf.data = NULL;
			path_conf.len = 0;
			continue;
		}

		/*
		 * compare path UID with device UID only if at least
		 * one valid path is left
		 * in other case the device UID may have changed and
		 * the first working path UID will be used as device UID
		 */
		if (dasd_path_get_opm(device) &&
		    dasd_eckd_compare_path_uid(device, &path_conf)) {
			/*
			 * the comparison was not successful
			 * rebuild the device UID with at least one
			 * known path in case a z/VM hyperswap command
			 * has changed the device
			 *
			 * after this compare again
			 *
			 * if either the rebuild or the recompare fails
			 * the path can not be used
			 */
			if (rebuild_device_uid(device, data) ||
			    dasd_eckd_compare_path_uid(
				    device, &path_conf)) {
				dasd_eckd_get_uid_string(&path_conf, print_uid);
				dev_err(&device->cdev->dev,
					"The newly added channel path %02X "
					"will not be used because it leads "
					"to a different device %s\n",
					lpm, print_uid);
				opm &= ~lpm;
				npm &= ~lpm;
				ppm &= ~lpm;
				cablepm |= lpm;
				continue;
			}
		}

		conf_data = kzalloc(DASD_ECKD_RCD_DATA_SIZE, GFP_KERNEL);
		if (conf_data) {
			memcpy(conf_data, data->rcd_buffer,
			       DASD_ECKD_RCD_DATA_SIZE);
		} else {
			/*
			 * path is operational but path config data could not
			 * be stored due to low mem condition
			 * add it to the error path mask and schedule a path
			 * verification later that this could be added again
			 */
			epm |= lpm;
		}
		pos = pathmask_to_pos(lpm);
		dasd_eckd_store_conf_data(device, conf_data, pos);

		/*
		 * There is a small chance that a path is lost again between
		 * above path verification and the following modification of
		 * the device opm mask. We could avoid that race here by using
		 * yet another path mask, but we rather deal with this unlikely
		 * situation in dasd_start_IO.
		 */
		spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
		if (!dasd_path_get_opm(device) && opm) {
			dasd_path_set_opm(device, opm);
			dasd_generic_path_operational(device);
		} else {
			dasd_path_add_opm(device, opm);
		}
		dasd_path_add_nppm(device, npm);
		dasd_path_add_ppm(device, ppm);
		if (epm) {
			dasd_path_add_tbvpm(device, epm);
			dasd_device_set_timer(device, 50);
		}
		dasd_path_add_cablepm(device, cablepm);
		dasd_path_add_nohpfpm(device, hpfpm);
		spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);

		dasd_path_create_kobj(device, pos);
	}
}

static void do_pe_handler_work(struct work_struct *work)
__context_unsafe(/* Conditional locking */)
{
	struct pe_handler_work_data *data;
	struct dasd_device *device;

	data = container_of(work, struct pe_handler_work_data, worker);
	device = data->device;

	/* delay path verification until device was resumed */
	if (test_bit(DASD_FLAG_SUSPENDED, &device->flags)) {
		schedule_work(work);
		return;
	}
	/* check if path verification already running and delay if so */
	if (test_and_set_bit(DASD_FLAG_PATH_VERIFY, &device->flags)) {
		schedule_work(work);
		return;
	}

	if (data->tbvpm)
		dasd_eckd_path_available_action(device, data);
	if (data->fcsecpm)
		dasd_eckd_read_fc_security(device);

	clear_bit(DASD_FLAG_PATH_VERIFY, &device->flags);
	dasd_put_device(device);
	if (data->isglobal)
		mutex_unlock(&dasd_pe_handler_mutex);
	else
		kfree(data);
}

static int dasd_eckd_pe_handler(struct dasd_device *device,
				__u8 tbvpm, __u8 fcsecpm)
__context_unsafe(/* Conditional locking */)
{
	struct pe_handler_work_data *data;

	data = kzalloc_obj(*data, GFP_ATOMIC | GFP_DMA);
	if (!data) {
		if (mutex_trylock(&dasd_pe_handler_mutex)) {
			data = pe_handler_worker;
			data->isglobal = 1;
		} else {
			return -ENOMEM;
		}
	}
	INIT_WORK(&data->worker, do_pe_handler_work);
	dasd_get_device(device);
	data->device = device;
	data->tbvpm = tbvpm;
	data->fcsecpm = fcsecpm;
	schedule_work(&data->worker);
	return 0;
}

static void dasd_eckd_reset_path(struct dasd_device *device, __u8 pm)
{
	struct dasd_eckd_private *private = device->private;
	unsigned long flags;

	if (!private)
		return;
	if (!private->fcx_max_data)
		private->fcx_max_data = get_fcx_max_data(device);
	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
	dasd_path_set_tbvpm(device, pm ? : dasd_path_get_notoperpm(device));
	dasd_schedule_device_bh(device);
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}

static int dasd_eckd_read_features(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_psf_prssd_data *prssdp;
	struct dasd_rssd_features *features;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int rc;

	memset(&private->features, 0, sizeof(struct dasd_rssd_features));
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
				   (sizeof(struct dasd_psf_prssd_data) +
				    sizeof(struct dasd_rssd_features)),
				   device, NULL);
	if (IS_ERR(cqr)) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s", "Could not "
				"allocate initialization request");
		return PTR_ERR(cqr);
	}
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 256;
	cqr->expires = 10 * HZ;

	/* Prepare for Read Subsystem Data */
	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
	prssdp->order = PSF_ORDER_PRSSD;
	prssdp->suborder = 0x41;	/* Read Feature Codes */
	/* all other bytes of prssdp must be zero */

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->count = sizeof(struct dasd_psf_prssd_data);
	ccw->flags |= CCW_FLAG_CC;
	ccw->cda = virt_to_dma32(prssdp);

	/* Read Subsystem Data - feature codes */
	features = (struct dasd_rssd_features *) (prssdp + 1);
	memset(features, 0, sizeof(struct dasd_rssd_features));

	ccw++;
	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
	ccw->count = sizeof(struct dasd_rssd_features);
	ccw->cda = virt_to_dma32(features);

	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	rc = dasd_sleep_on(cqr);
	if (rc == 0) {
		prssdp = (struct dasd_psf_prssd_data *) cqr->data;
		features = (struct dasd_rssd_features *) (prssdp + 1);
		memcpy(&private->features, features,
		       sizeof(struct dasd_rssd_features));
	} else
		dev_warn(&device->cdev->dev, "Reading device feature codes"
			 " failed with rc=%d\n", rc);
	dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/* Read Volume Information - Volume Storage Query */
static int dasd_eckd_read_vol_info(struct dasd_device *device)
__context_unsafe(/* Conditional locking */)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_psf_prssd_data *prssdp;
	struct dasd_rssd_vsq *vsq;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int useglobal;
	int rc;

	/* This command cannot be executed on an alias device */
	if (private->uid.type == UA_BASE_PAV_ALIAS ||
	    private->uid.type == UA_HYPER_PAV_ALIAS)
		return 0;

	useglobal = 0;
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2 /* PSF + RSSD */,
				   sizeof(*prssdp) + sizeof(*vsq), device, NULL);
	if (IS_ERR(cqr)) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate initialization request");
		mutex_lock(&dasd_vol_info_mutex);
		useglobal = 1;
		cqr = &dasd_vol_info_req->cqr;
		memset(cqr, 0, sizeof(*cqr));
		memset(dasd_vol_info_req, 0, sizeof(*dasd_vol_info_req));
		cqr->cpaddr = &dasd_vol_info_req->ccw;
		cqr->data = &dasd_vol_info_req->data;
		cqr->magic = DASD_ECKD_MAGIC;
	}

	/* Prepare for Read Subsystem Data */
	prssdp = cqr->data;
	prssdp->order = PSF_ORDER_PRSSD;
	prssdp->suborder = PSF_SUBORDER_VSQ;	/* Volume Storage Query */
	prssdp->lss = READ_ONCE(private->ned_lss);
	prssdp->volume = READ_ONCE(private->ned_ua);

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->count = sizeof(*prssdp);
	ccw->flags |= CCW_FLAG_CC;
	ccw->cda = virt_to_dma32(prssdp);

	/* Read Subsystem Data - Volume Storage Query */
	vsq = (struct dasd_rssd_vsq *)(prssdp + 1);
	memset(vsq, 0, sizeof(*vsq));

	ccw++;
	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
	ccw->count = sizeof(*vsq);
	ccw->flags |= CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(vsq);

	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 256;
	cqr->expires = device->default_expires * HZ;
	/* The command might not be supported. Suppress the error output */
	__set_bit(DASD_CQR_SUPPRESS_CR, &cqr->flags);

	rc = dasd_sleep_on_interruptible(cqr);
	if (rc == 0) {
		memcpy(&private->vsq, vsq, sizeof(*vsq));
	} else {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
				"Reading the volume storage information failed with rc=%d", rc);
	}

	if (useglobal)
		mutex_unlock(&dasd_vol_info_mutex);
	else
		dasd_sfree_request(cqr, cqr->memdev);

	return rc;
}

/* Hardware/volume ESE capability, from the Volume Storage Query. */
static int dasd_eckd_ese_capable(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	if (!private)
		return 0;

	return private->vsq.vol_info.ese;
}

/*
 * Whether the volume is to be handled as ESE (thin). This reflects the state
 * of the data, not the hardware: a volume copied off ESE storage onto other
 * hardware still needs ESE handling. The on-disk format label is authoritative
 * when present; without it (e.g. a volume formatted by an older driver) fall
 * back to the hardware ESE field.
 *
 * Only the F_ESE flag gates this. An ESE volume is thin regardless of whether
 * it was quick- or full-formatted (tracks are allocated on write, and discard
 * re-thins a full one).
 */
static int dasd_eckd_is_ese(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	/* sysfs may read this during set_online before private is allocated */
	if (!private)
		return 0;

	if (private->ese_label_valid)
		return !!(private->ese_label.flags & DASD_ESE_LABEL_F_ESE);

	return dasd_eckd_ese_capable(device);
}

/*
 * Whether the volume is formatted on demand (thin), as opposed to fully
 * formatted. This is the format mode, not the hardware ESE capability. When a
 * label is present it is authoritative (F_QUICK). Without a label the mode is
 * unknown, but an ESE volume is still handled on demand (NRF triggers the
 * format), so fall back to the ESE state to stay consistent with the driver's
 * behavior on older, label-less volumes.
 */
static int dasd_eckd_on_demand_format(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	/* sysfs may read this during set_online before private is allocated */
	if (!private)
		return 0;

	if (private->ese_label_valid)
		return !!(private->ese_label.flags & DASD_ESE_LABEL_F_QUICK);

	return dasd_eckd_is_ese(device);
}

static int dasd_eckd_ext_pool_id(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	if (!private)
		return 0;

	return private->vsq.extent_pool_id;
}

/*
 * This value represents the total amount of available space. As more space is
 * allocated by ESE volumes, this value will decrease.
 * The data for this value is therefore updated on any call.
 */
static int dasd_eckd_space_configured(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	int rc;

	if (!private)
		return 0;

	rc = dasd_eckd_read_vol_info(device);

	return rc ? : private->vsq.space_configured;
}

/*
 * The value of space allocated by an ESE volume may have changed and is
 * therefore updated on any call.
 */
static int dasd_eckd_space_allocated(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	int rc;

	if (!private)
		return 0;

	rc = dasd_eckd_read_vol_info(device);

	return rc ? : private->vsq.space_allocated;
}

static int dasd_eckd_logical_capacity(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	if (!private)
		return 0;

	return private->vsq.logical_capacity;
}

static void dasd_eckd_ext_pool_exhaust_work(struct work_struct *work)
{
	struct ext_pool_exhaust_work_data *data;
	struct dasd_device *device;
	struct dasd_device *base;

	data = container_of(work, struct ext_pool_exhaust_work_data, worker);
	device = data->device;
	base = data->base;

	if (!base)
		base = device;
	if (dasd_eckd_space_configured(base) != 0) {
		dasd_generic_space_avail(device);
	} else {
		dev_warn(&device->cdev->dev, "No space left in the extent pool\n");
		DBF_DEV_EVENT(DBF_WARNING, device, "%s", "out of space");
	}

	dasd_put_device(device);
	kfree(data);
}

static int dasd_eckd_ext_pool_exhaust(struct dasd_device *device,
				      struct dasd_ccw_req *cqr)
{
	struct ext_pool_exhaust_work_data *data;

	data = kzalloc_obj(*data, GFP_ATOMIC);
	if (!data)
		return -ENOMEM;
	INIT_WORK(&data->worker, dasd_eckd_ext_pool_exhaust_work);
	dasd_get_device(device);
	data->device = device;

	if (cqr->block)
		data->base = cqr->block->base;
	else if (cqr->basedev)
		data->base = cqr->basedev;
	else
		data->base = NULL;

	schedule_work(&data->worker);

	return 0;
}

static void dasd_eckd_cpy_ext_pool_data(struct dasd_device *device,
					struct dasd_rssd_lcq *lcq)
{
	struct dasd_eckd_private *private = device->private;
	int pool_id = dasd_eckd_ext_pool_id(device);
	struct dasd_ext_pool_sum eps;
	int i;

	for (i = 0; i < lcq->pool_count; i++) {
		eps = lcq->ext_pool_sum[i];
		if (eps.pool_id == pool_id) {
			memcpy(&private->eps, &eps,
			       sizeof(struct dasd_ext_pool_sum));
		}
	}
}

/* Read Extent Pool Information - Logical Configuration Query */
static int dasd_eckd_read_ext_pool_info(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_psf_prssd_data *prssdp;
	struct dasd_rssd_lcq *lcq;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int rc;

	/* This command cannot be executed on an alias device */
	if (private->uid.type == UA_BASE_PAV_ALIAS ||
	    private->uid.type == UA_HYPER_PAV_ALIAS)
		return 0;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2 /* PSF + RSSD */,
				   sizeof(*prssdp) + sizeof(*lcq), device, NULL);
	if (IS_ERR(cqr)) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate initialization request");
		return PTR_ERR(cqr);
	}

	/* Prepare for Read Subsystem Data */
	prssdp = cqr->data;
	memset(prssdp, 0, sizeof(*prssdp));
	prssdp->order = PSF_ORDER_PRSSD;
	prssdp->suborder = PSF_SUBORDER_LCQ;	/* Logical Configuration Query */

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->count = sizeof(*prssdp);
	ccw->flags |= CCW_FLAG_CC;
	ccw->cda = virt_to_dma32(prssdp);

	lcq = (struct dasd_rssd_lcq *)(prssdp + 1);
	memset(lcq, 0, sizeof(*lcq));

	ccw++;
	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
	ccw->count = sizeof(*lcq);
	ccw->flags |= CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(lcq);

	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 256;
	cqr->expires = device->default_expires * HZ;
	/* The command might not be supported. Suppress the error output */
	__set_bit(DASD_CQR_SUPPRESS_CR, &cqr->flags);

	rc = dasd_sleep_on_interruptible(cqr);
	if (rc == 0) {
		dasd_eckd_cpy_ext_pool_data(device, lcq);
	} else {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
				"Reading the logical configuration failed with rc=%d", rc);
	}

	dasd_sfree_request(cqr, cqr->memdev);

	return rc;
}

/*
 * Depending on the device type, the extent size is specified either as
 * cylinders per extent (CKD) or size per extent (FBA)
 * A 1GB size corresponds to 1113cyl, and 16MB to 21cyl.
 */
static int dasd_eckd_ext_size(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_ext_pool_sum eps;

	if (!private)
		return 0;
	eps = private->eps;

	if (!eps.flags.extent_size_valid)
		return 0;
	if (eps.extent_size.size_1G)
		return 1113;
	if (eps.extent_size.size_16M)
		return 21;

	return 0;
}

static int dasd_eckd_ext_pool_warn_thrshld(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	if (!private)
		return 0;

	return private->eps.warn_thrshld;
}

static int dasd_eckd_ext_pool_cap_at_warnlevel(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	if (!private)
		return 0;

	return private->eps.flags.capacity_at_warnlevel;
}

/*
 * Extent Pool out of space
 */
static int dasd_eckd_ext_pool_oos(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	if (!private)
		return 0;

	return private->eps.flags.pool_oos;
}

/*
 * Build CP for Perform Subsystem Function - SSC.
 */
static struct dasd_ccw_req *dasd_eckd_build_psf_ssc(struct dasd_device *device,
						    int enable_pav)
{
	struct dasd_ccw_req *cqr;
	struct dasd_psf_ssc_data *psf_ssc_data;
	struct ccw1 *ccw;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ ,
				  sizeof(struct dasd_psf_ssc_data),
				   device, NULL);

	if (IS_ERR(cqr)) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			   "Could not allocate PSF-SSC request");
		return cqr;
	}
	psf_ssc_data = (struct dasd_psf_ssc_data *)cqr->data;
	psf_ssc_data->order = PSF_ORDER_SSC;
	psf_ssc_data->suborder = 0xc0;
	if (enable_pav) {
		psf_ssc_data->suborder |= 0x08;
		psf_ssc_data->reserved[0] = 0x88;
	}
	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->cda = virt_to_dma32(psf_ssc_data);
	ccw->count = 66;

	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 256;
	cqr->expires = 10*HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	return cqr;
}

/*
 * Perform Subsystem Function.
 * It is necessary to trigger CIO for channel revalidation since this
 * call might change behaviour of DASD devices.
 */
static int
dasd_eckd_psf_ssc(struct dasd_device *device, int enable_pav,
		  unsigned long flags)
{
	struct dasd_ccw_req *cqr;
	int rc;

	cqr = dasd_eckd_build_psf_ssc(device, enable_pav);
	if (IS_ERR(cqr))
		return PTR_ERR(cqr);

	/*
	 * set flags e.g. turn on failfast, to prevent blocking
	 * the calling function should handle failed requests
	 */
	cqr->flags |= flags;

	rc = dasd_sleep_on(cqr);
	if (!rc)
		/* trigger CIO to reprobe devices */
		css_schedule_reprobe();
	else if (cqr->intrc == -EAGAIN)
		rc = -EAGAIN;

	dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/*
 * Valid storage server of current device.
 */
static int dasd_eckd_validate_server(struct dasd_device *device,
				     unsigned long flags)
{
	struct dasd_eckd_private *private = device->private;
	int enable_pav, rc;

	if (private->uid.type == UA_BASE_PAV_ALIAS ||
	    private->uid.type == UA_HYPER_PAV_ALIAS)
		return 0;
	if (dasd_nopav || machine_is_vm())
		enable_pav = 0;
	else
		enable_pav = 1;
	rc = dasd_eckd_psf_ssc(device, enable_pav, flags);

	/* may be requested feature is not available on server,
	 * therefore just report error and go ahead */
	DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "PSF-SSC for SSID %04x "
			"returned rc=%d", private->uid.ssid, rc);
	return rc;
}

/*
 * worker to do a validate server in case of a lost pathgroup
 */
static void dasd_eckd_do_validate_server(struct work_struct *work)
{
	struct dasd_device *device = container_of(work, struct dasd_device,
						  kick_validate);
	unsigned long flags = 0;

	set_bit(DASD_CQR_FLAGS_FAILFAST, &flags);
	if (dasd_eckd_validate_server(device, flags)
	    == -EAGAIN) {
		/* schedule worker again if failed */
		schedule_work(&device->kick_validate);
		return;
	}

	dasd_put_device(device);
}

static void dasd_eckd_kick_validate_server(struct dasd_device *device)
{
	dasd_get_device(device);
	/* exit if device not online or in offline processing */
	if (test_bit(DASD_FLAG_OFFLINE, &device->flags) ||
	   device->state < DASD_STATE_ONLINE) {
		dasd_put_device(device);
		return;
	}
	/* queue call to do_validate_server to the kernel event daemon. */
	if (!schedule_work(&device->kick_validate))
		dasd_put_device(device);
}

/*
 * return if the device is the copy relation primary if a copy relation is active
 */
static int dasd_device_is_primary(struct dasd_device *device)
{
	if (!device->copy)
		return 1;

	if (device->copy->active->device == device)
		return 1;

	return 0;
}

static int dasd_eckd_alloc_block(struct dasd_device *device)
{
	struct dasd_block *block;
	struct dasd_uid temp_uid;

	if (!dasd_device_is_primary(device))
		return 0;

	dasd_eckd_get_uid(device, &temp_uid);
	if (temp_uid.type == UA_BASE_DEVICE) {
		block = dasd_alloc_block();
		if (IS_ERR(block)) {
			DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
					"could not allocate dasd block structure");
			return PTR_ERR(block);
		}
		device->block = block;
		block->base = device;
	}
	return 0;
}

static bool dasd_eckd_pprc_enabled(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	return private->rdc_data.facilities.PPRC_enabled;
}

/*
 * Read the on-disk format label from track 0, record 4. On a formatted volume
 * R4 holds the label as its record data; on an unformatted (fresh ESE) or
 * label-less volume the read returns No Record Found, which is expected and
 * leaves the cache invalid so is_ese() falls back to the hardware field.
 */
static void dasd_eckd_read_format_label(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_format_label *label;
	struct DE_eckd_data *dedata;
	struct LO_eckd_data *lodata;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;

	private->ese_label_valid = false;

	/* The label lives on the base volume; aliases have none of their own. */
	if (private->uid.type == UA_BASE_PAV_ALIAS ||
	    private->uid.type == UA_HYPER_PAV_ALIAS)
		return;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 3 /* DE + LO + READ */,
				   sizeof(*dedata) + sizeof(*lodata) +
				   sizeof(*label), device, NULL);
	if (IS_ERR(cqr))
		return;

	dedata = cqr->data;
	lodata = (struct LO_eckd_data *)(dedata + 1);
	label = (struct dasd_format_label *)(lodata + 1);

	ccw = cqr->cpaddr;
	define_extent(ccw++, dedata, 0, 0, DASD_ECKD_CCW_READ, device, 0);
	ccw[-1].flags |= CCW_FLAG_CC;
	locate_record(ccw++, lodata, 0, 4, 1, DASD_ECKD_CCW_READ, device,
		      sizeof(*label));
	ccw[-1].flags |= CCW_FLAG_CC;
	ccw->cmd_code = DASD_ECKD_CCW_READ;
	ccw->count = sizeof(*label);
	ccw->flags = CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(label);

	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 256;
	cqr->expires = 10 * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	/* R4 may be absent (unformatted) or larger than the label. */
	set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
	set_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags);

	if (!dasd_sleep_on(cqr) &&
	    label->magic == DASD_ESE_LABEL_MAGIC &&
	    label->version == DASD_ESE_LABEL_VERSION) {
		private->ese_label = *label;
		private->ese_label_valid = true;
	}
	dasd_sfree_request(cqr, device);
}

/*
 * Check device characteristics.
 * If the device is accessible using ECKD discipline, the device is enabled.
 */
static int
dasd_eckd_check_characteristics(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	int rc, i;
	int readonly;
	unsigned long value;

	/* setup work queue for validate server*/
	INIT_WORK(&device->kick_validate, dasd_eckd_do_validate_server);
	/* setup work queue for summary unit check */
	INIT_WORK(&device->suc_work, dasd_alias_handle_summary_unit_check);

	if (!ccw_device_is_pathgroup(device->cdev)) {
		dev_warn(&device->cdev->dev,
			 "A channel path group could not be established\n");
		return -EIO;
	}
	if (!ccw_device_is_multipath(device->cdev)) {
		dev_info(&device->cdev->dev,
			 "The DASD is not operating in multipath mode\n");
	}
	if (!private) {
		private = kzalloc_obj(*private, GFP_KERNEL | GFP_DMA);
		if (!private) {
			dev_warn(&device->cdev->dev,
				 "Allocating memory for private DASD data "
				 "failed\n");
			return -ENOMEM;
		}
		device->private = private;
	} else {
		memset(private, 0, sizeof(*private));
	}
	/* Invalidate status of initial analysis. */
	private->init_cqr_status = -1;
	/* Set default cache operations. */
	private->attrib.operation = DASD_NORMAL_CACHE;
	private->attrib.nr_cyl = 0;

	/* Read Configuration Data */
	rc = dasd_eckd_read_conf(device);
	if (rc)
		goto out_err1;

	/* set some default values */
	device->default_expires = DASD_EXPIRES;
	device->default_retries = DASD_RETRIES;
	device->path_thrhld = DASD_ECKD_PATH_THRHLD;
	device->path_interval = DASD_ECKD_PATH_INTERVAL;
	device->aq_timeouts = DASD_RETRIES_MAX;

	if (private->conf.gneq) {
		value = 1;
		for (i = 0; i < private->conf.gneq->timeout.value; i++)
			value = 10 * value;
		value = value * private->conf.gneq->timeout.number;
		/* do not accept useless values */
		if (value != 0 && value <= DASD_EXPIRES_MAX)
			device->default_expires = value;
	}

	/* Read Device Characteristics */
	rc = dasd_generic_read_dev_chars(device, DASD_ECKD_MAGIC,
					 &private->rdc_data, 64);
	if (rc) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
				"Read device characteristic failed, rc=%d", rc);
		goto out_err1;
	}

	/* setup PPRC for device from devmap */
	rc = dasd_devmap_set_device_copy_relation(device->cdev,
						  dasd_eckd_pprc_enabled(device));
	if (rc) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
				"copy relation setup failed, rc=%d", rc);
		goto out_err1;
	}

	/* check if block device is needed and allocate in case */
	rc = dasd_eckd_alloc_block(device);
	if (rc)
		goto out_err1;

	/* register lcu with alias handling, enable PAV */
	rc = dasd_alias_make_device_known_to_lcu(device);
	if (rc)
		goto out_err2;

	dasd_eckd_validate_server(device, 0);

	/* device may report different configuration data after LCU setup */
	rc = dasd_eckd_read_conf(device);
	if (rc)
		goto out_err3;

	dasd_eckd_read_fc_security(device);
	dasd_path_create_kobjects(device);

	/* Read Feature Codes */
	dasd_eckd_read_features(device);

	/* Read Volume Information */
	dasd_eckd_read_vol_info(device);

	/*
	 * Advertise discard through the device feature so the block layer sets
	 * up discard limits. Discard releases allocated space, so require a thin
	 * (ESE) volume whose storage reports support for the space-release
	 * function. Raw-track access bypasses the normal block CCW path (discard
	 * would reach the raw builder, which has no record data), so exclude it.
	 */
	if (dasd_eckd_ese_capable(device) &&
	    (private->features.feature[56] & 0x01) &&
	    !(device->features & DASD_FEATURE_USERAW))
		device->features |= DASD_FEATURE_DISCARD;

	/* Read the on-disk format label for ESE detection */
	dasd_eckd_read_format_label(device);

	/*
	 * is_ese() now reflects the real ESE state (vsq + on-disk label), so
	 * the adaptive heuristic can be derived correctly for this device.
	 */
	device->ft_bias = min_t(unsigned int, full_track_bias, DASD_FT_BIAS_MAX);
	dasd_ft_bias_apply(device);

	/* Read Extent Pool Information */
	dasd_eckd_read_ext_pool_info(device);

	if ((device->features & DASD_FEATURE_USERAW) &&
	    !(private->rdc_data.facilities.RT_in_LR)) {
		dev_err(&device->cdev->dev, "The storage server does not "
			"support raw-track access\n");
		rc = -EINVAL;
		goto out_err3;
	}

	/* find the valid cylinder size */
	if (private->rdc_data.no_cyl == LV_COMPAT_CYL &&
	    private->rdc_data.long_no_cyl)
		private->real_cyl = private->rdc_data.long_no_cyl;
	else
		private->real_cyl = private->rdc_data.no_cyl;

	private->fcx_max_data = get_fcx_max_data(device);

	readonly = dasd_device_is_ro(device);
	if (readonly)
		set_bit(DASD_FLAG_DEVICE_RO, &device->flags);

	dev_info(&device->cdev->dev, "New DASD %04X/%02X (CU %04X/%02X) "
		 "with %d cylinders, %d heads, %d sectors%s\n",
		 private->rdc_data.dev_type,
		 private->rdc_data.dev_model,
		 private->rdc_data.cu_type,
		 private->rdc_data.cu_model.model,
		 private->real_cyl,
		 private->rdc_data.trk_per_cyl,
		 private->rdc_data.sec_per_trk,
		 readonly ? ", read-only device" : "");
	return 0;

out_err3:
	dasd_alias_disconnect_device_from_lcu(device);
out_err2:
	dasd_free_block(device->block);
	device->block = NULL;
out_err1:
	dasd_eckd_clear_conf_data(device);
	dasd_path_remove_kobjects(device);
	kfree(device->private);
	device->private = NULL;
	return rc;
}

static void dasd_eckd_uncheck_device(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	if (!private)
		return;

	dasd_alias_disconnect_device_from_lcu(device);
	private->conf.ned = NULL;
	private->conf.sneq = NULL;
	private->conf.vdsneq = NULL;
	private->conf.gneq = NULL;
	dasd_eckd_clear_conf_data(device);
	dasd_path_remove_kobjects(device);
}

static struct dasd_ccw_req *
dasd_eckd_analysis_ccw(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	struct eckd_count *count_data;
	struct LO_eckd_data *LO_data;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int cplength, datasize;
	int i;

	cplength = 8;
	datasize = sizeof(struct DE_eckd_data) + 2*sizeof(struct LO_eckd_data);
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize, device,
				   NULL);
	if (IS_ERR(cqr))
		return cqr;
	ccw = cqr->cpaddr;
	/* Define extent for the first 2 tracks. */
	define_extent(ccw++, cqr->data, 0, 1,
		      DASD_ECKD_CCW_READ_COUNT, device, 0);
	LO_data = cqr->data + sizeof(struct DE_eckd_data);
	/* Locate record for the first 4 records on track 0. */
	ccw[-1].flags |= CCW_FLAG_CC;
	locate_record(ccw++, LO_data++, 0, 0, 4,
		      DASD_ECKD_CCW_READ_COUNT, device, 0);

	count_data = private->count_area;
	for (i = 0; i < 4; i++) {
		ccw[-1].flags |= CCW_FLAG_CC;
		ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
		ccw->flags = 0;
		ccw->count = 8;
		ccw->cda = virt_to_dma32(count_data);
		ccw++;
		count_data++;
	}

	/* Locate record for the first record on track 1. */
	ccw[-1].flags |= CCW_FLAG_CC;
	locate_record(ccw++, LO_data++, 1, 0, 1,
		      DASD_ECKD_CCW_READ_COUNT, device, 0);
	/* Read count ccw. */
	ccw[-1].flags |= CCW_FLAG_CC;
	ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
	ccw->flags = 0;
	ccw->count = 8;
	ccw->cda = virt_to_dma32(count_data);

	cqr->block = NULL;
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->retries = 255;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	/* Set flags to suppress output for expected errors */
	set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
	set_bit(DASD_CQR_SUPPRESS_IT, &cqr->flags);

	return cqr;
}

/* differentiate between 'no record found' and any other error */
static int dasd_eckd_analysis_evaluation(struct dasd_ccw_req *init_cqr)
{
	char *sense;
	if (init_cqr->status == DASD_CQR_DONE)
		return INIT_CQR_OK;
	else if (init_cqr->status == DASD_CQR_NEED_ERP ||
		 init_cqr->status == DASD_CQR_FAILED) {
		sense = dasd_get_sense(&init_cqr->irb);
		if (sense && (sense[1] & SNS1_NO_REC_FOUND))
			return INIT_CQR_UNFORMATTED;
		else
			return INIT_CQR_ERROR;
	} else
		return INIT_CQR_ERROR;
}

/*
 * This is the callback function for the init_analysis cqr. It saves
 * the status of the initial analysis ccw before it frees it and kicks
 * the device to continue the startup sequence. This will call
 * dasd_eckd_do_analysis again (if the devices has not been marked
 * for deletion in the meantime).
 */
static void dasd_eckd_analysis_callback(struct dasd_ccw_req *init_cqr,
					void *data)
{
	struct dasd_device *device = init_cqr->startdev;
	struct dasd_eckd_private *private = device->private;

	private->init_cqr_status = dasd_eckd_analysis_evaluation(init_cqr);
	dasd_sfree_request(init_cqr, device);
	dasd_kick_device(device);
}

static int dasd_eckd_start_analysis(struct dasd_block *block)
{
	struct dasd_ccw_req *init_cqr;

	init_cqr = dasd_eckd_analysis_ccw(block->base);
	if (IS_ERR(init_cqr))
		return PTR_ERR(init_cqr);
	init_cqr->callback = dasd_eckd_analysis_callback;
	init_cqr->callback_data = NULL;
	init_cqr->expires = 5*HZ;
	/* first try without ERP, so we can later handle unformatted
	 * devices as special case
	 */
	clear_bit(DASD_CQR_FLAGS_USE_ERP, &init_cqr->flags);
	init_cqr->retries = 0;
	dasd_add_request_head(init_cqr);
	return -EAGAIN;
}

static int dasd_eckd_end_analysis(struct dasd_block *block)
{
	struct dasd_device *device = block->base;
	struct dasd_eckd_private *private = device->private;
	struct eckd_count *count_area;
	const char *ese_str, *fmt_str;
	unsigned int sb, blk_per_trk;
	int status, i;
	struct dasd_ccw_req *init_cqr;

	status = private->init_cqr_status;
	private->init_cqr_status = -1;
	if (status == INIT_CQR_ERROR) {
		/* try again, this time with full ERP */
		init_cqr = dasd_eckd_analysis_ccw(device);
		dasd_sleep_on(init_cqr);
		status = dasd_eckd_analysis_evaluation(init_cqr);
		dasd_sfree_request(init_cqr, device);
	}

	if (device->features & DASD_FEATURE_USERAW) {
		block->bp_block = DASD_RAW_BLOCKSIZE;
		blk_per_trk = DASD_RAW_BLOCK_PER_TRACK;
		block->s2b_shift = 3;
		goto raw;
	}

	if (status == INIT_CQR_UNFORMATTED) {
		dev_warn(&device->cdev->dev, "The DASD is not formatted\n");
		return -EMEDIUMTYPE;
	} else if (status == INIT_CQR_ERROR) {
		dev_err(&device->cdev->dev,
			"Detecting the DASD disk layout failed because "
			"of an I/O error\n");
		return -EIO;
	}

	private->uses_cdl = 1;
	/* Check Track 0 for Compatible Disk Layout */
	count_area = NULL;
	for (i = 0; i < 3; i++) {
		if (private->count_area[i].kl != 4 ||
		    private->count_area[i].dl != dasd_eckd_cdl_reclen(i) - 4 ||
		    private->count_area[i].cyl != 0 ||
		    private->count_area[i].head != count_area_head[i] ||
		    private->count_area[i].record != count_area_rec[i]) {
			private->uses_cdl = 0;
			break;
		}
	}
	if (i == 3)
		count_area = &private->count_area[3];

	if (private->uses_cdl == 0) {
		for (i = 0; i < 5; i++) {
			if ((private->count_area[i].kl != 0) ||
			    (private->count_area[i].dl !=
			     private->count_area[0].dl) ||
			    private->count_area[i].cyl !=  0 ||
			    private->count_area[i].head != count_area_head[i] ||
			    private->count_area[i].record != count_area_rec[i])
				break;
		}
		if (i == 5)
			count_area = &private->count_area[0];
	} else {
		if (private->count_area[3].record == 1)
			dev_warn(&device->cdev->dev,
				 "Track 0 has no records following the VTOC\n");
	}

	if (count_area != NULL && count_area->kl == 0) {
		/* we found nothing violating our disk layout */
		if (dasd_check_blocksize(count_area->dl) == 0)
			block->bp_block = count_area->dl;
	}
	if (block->bp_block == 0) {
		dev_warn(&device->cdev->dev,
			 "The disk layout of the DASD is not supported\n");
		return -EMEDIUMTYPE;
	}
	block->s2b_shift = 0;	/* bits to shift 512 to get a block */
	for (sb = 512; sb < block->bp_block; sb = sb << 1)
		block->s2b_shift++;

	blk_per_trk = recs_per_track(&private->rdc_data, 0, block->bp_block);

raw:
	block->blocks = ((unsigned long) private->real_cyl *
			  private->rdc_data.trk_per_cyl *
			  blk_per_trk);

	/*
	 * Report the ESE hardware capability and the format mode. The mode
	 * comes from dasd_eckd_on_demand_format() (the on-disk label, or the
	 * ESE state when no label is present), matching the on_demand_formatting
	 * sysfs attribute.
	 */
	ese_str = dasd_eckd_ese_capable(device) ? ", ESE" : "";
	fmt_str = "";
	if (dasd_eckd_on_demand_format(device))
		fmt_str = ", on-demand format";
	else if (dasd_eckd_ese_capable(device))
		fmt_str = ", full format";

	dev_info(&device->cdev->dev,
		 "DASD with %u KB/block, %lu KB total size, %u KB/track, %s%s%s\n",
		 (block->bp_block >> 10),
		 (((unsigned long) private->real_cyl *
		   private->rdc_data.trk_per_cyl *
		   blk_per_trk * (block->bp_block >> 9)) >> 1),
		 ((blk_per_trk * block->bp_block) >> 10),
		 private->uses_cdl ?
		 "compatible disk layout" : "linux disk layout",
		 ese_str, fmt_str);

	return 0;
}

static int dasd_eckd_do_analysis(struct dasd_block *block)
{
	struct dasd_eckd_private *private = block->base->private;

	if (private->init_cqr_status < 0)
		return dasd_eckd_start_analysis(block);
	else
		return dasd_eckd_end_analysis(block);
}

static int dasd_eckd_basic_to_ready(struct dasd_device *device)
{
	return dasd_alias_add_device(device);
};

static int dasd_eckd_online_to_ready(struct dasd_device *device)
{
	if (cancel_work_sync(&device->reload_device))
		dasd_put_device(device);
	if (cancel_work_sync(&device->kick_validate))
		dasd_put_device(device);

	return 0;
};

static int dasd_eckd_basic_to_known(struct dasd_device *device)
{
	return dasd_alias_remove_device(device);
};

static int
dasd_eckd_fill_geometry(struct dasd_block *block, struct hd_geometry *geo)
{
	struct dasd_eckd_private *private = block->base->private;

	if (dasd_check_blocksize(block->bp_block) == 0) {
		geo->sectors = recs_per_track(&private->rdc_data,
					      0, block->bp_block);
	}
	geo->cylinders = private->rdc_data.no_cyl;
	geo->heads = private->rdc_data.trk_per_cyl;
	return 0;
}

/*
 * Build the TCW request for the format check
 */
static struct dasd_ccw_req *
dasd_eckd_build_check_tcw(struct dasd_device *base, struct format_data_t *fdata,
			  int enable_pav, struct eckd_count *fmt_buffer,
			  int rpt)
{
	struct dasd_eckd_private *start_priv;
	struct dasd_device *startdev = NULL;
	struct tidaw *last_tidaw = NULL;
	struct dasd_ccw_req *cqr;
	struct itcw *itcw;
	int itcw_size;
	int count;
	int rc;
	int i;

	if (enable_pav)
		startdev = dasd_alias_get_start_dev(base);

	if (!startdev)
		startdev = base;

	start_priv = startdev->private;

	count = rpt * (fdata->stop_unit - fdata->start_unit + 1);

	/*
	 * we're adding 'count' amount of tidaw to the itcw.
	 * calculate the corresponding itcw_size
	 */
	itcw_size = itcw_calc_size(0, count, 0);

	cqr = dasd_fmalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev);
	if (IS_ERR(cqr))
		return cqr;

	start_priv->count++;

	itcw = itcw_init(cqr->data, itcw_size, ITCW_OP_READ, 0, count, 0);
	if (IS_ERR(itcw)) {
		rc = -EINVAL;
		goto out_err;
	}

	cqr->cpaddr = itcw_get_tcw(itcw);
	rc = prepare_itcw(itcw, fdata->start_unit, fdata->stop_unit,
			  DASD_ECKD_CCW_READ_COUNT_MT, base, startdev, 0, count,
			  sizeof(struct eckd_count),
			  count * sizeof(struct eckd_count), 0, rpt);
	if (rc)
		goto out_err;

	for (i = 0; i < count; i++) {
		last_tidaw = itcw_add_tidaw(itcw, 0, fmt_buffer++,
					    sizeof(struct eckd_count));
		if (IS_ERR(last_tidaw)) {
			rc = -EINVAL;
			goto out_err;
		}
	}

	last_tidaw->flags |= TIDAW_FLAGS_LAST;
	itcw_finalize(itcw);

	cqr->cpmode = 1;
	cqr->startdev = startdev;
	cqr->memdev = startdev;
	cqr->basedev = base;
	cqr->retries = startdev->default_retries;
	cqr->expires = startdev->default_expires * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	/* Set flags to suppress output for expected errors */
	set_bit(DASD_CQR_SUPPRESS_IL, &cqr->flags);

	return cqr;

out_err:
	dasd_sfree_request(cqr, startdev);

	return ERR_PTR(rc);
}

/*
 * Build the CCW request for the format check
 */
static struct dasd_ccw_req *
dasd_eckd_build_check(struct dasd_device *base, struct format_data_t *fdata,
		      int enable_pav, struct eckd_count *fmt_buffer, int rpt)
{
	struct dasd_eckd_private *start_priv;
	struct dasd_eckd_private *base_priv;
	struct dasd_device *startdev = NULL;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	void *data;
	int cplength, datasize;
	int use_prefix;
	int count;
	int i;

	if (enable_pav)
		startdev = dasd_alias_get_start_dev(base);

	if (!startdev)
		startdev = base;

	start_priv = startdev->private;
	base_priv = base->private;

	count = rpt * (fdata->stop_unit - fdata->start_unit + 1);

	use_prefix = base_priv->features.feature[8] & 0x01;

	if (use_prefix) {
		cplength = 1;
		datasize = sizeof(struct PFX_eckd_data);
	} else {
		cplength = 2;
		datasize = sizeof(struct DE_eckd_data) +
			sizeof(struct LO_eckd_data);
	}
	cplength += count;

	cqr = dasd_fmalloc_request(DASD_ECKD_MAGIC, cplength, datasize, startdev);
	if (IS_ERR(cqr))
		return cqr;

	start_priv->count++;
	data = cqr->data;
	ccw = cqr->cpaddr;

	if (use_prefix) {
		prefix_LRE(ccw++, data, fdata->start_unit, fdata->stop_unit,
			   DASD_ECKD_CCW_READ_COUNT, base, startdev, 1, 0,
			   count, 0, 0);
	} else {
		define_extent(ccw++, data, fdata->start_unit, fdata->stop_unit,
			      DASD_ECKD_CCW_READ_COUNT, startdev, 0);

		data += sizeof(struct DE_eckd_data);
		ccw[-1].flags |= CCW_FLAG_CC;

		locate_record(ccw++, data, fdata->start_unit, 0, count,
			      DASD_ECKD_CCW_READ_COUNT, base, 0);
	}

	for (i = 0; i < count; i++) {
		ccw[-1].flags |= CCW_FLAG_CC;
		ccw->cmd_code = DASD_ECKD_CCW_READ_COUNT;
		ccw->flags = CCW_FLAG_SLI;
		ccw->count = 8;
		ccw->cda = virt_to_dma32(fmt_buffer);
		ccw++;
		fmt_buffer++;
	}

	cqr->startdev = startdev;
	cqr->memdev = startdev;
	cqr->basedev = base;
	cqr->retries = DASD_RETRIES;
	cqr->expires = startdev->default_expires * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	/* Set flags to suppress output for expected errors */
	set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);

	return cqr;
}

/* Fill the format label into a R4 record buffer, zero-padded to blksize. */
static void dasd_eckd_fill_format_label(struct dasd_device *device, void *data,
					unsigned int blksize)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_format_label *label = data;

	memset(label, 0, blksize);
	label->magic = DASD_ESE_LABEL_MAGIC;
	label->version = DASD_ESE_LABEL_VERSION;
	/*
	 * F_ESE records the hardware capability at format time, not is_ese():
	 * is_ese() is derived from the label, so using it here would let the
	 * flag flip on repeated quick/full reformats.
	 */
	if (dasd_eckd_ese_capable(device))
		label->flags |= DASD_ESE_LABEL_F_ESE;
	if (private->ese_format_quick)
		label->flags |= DASD_ESE_LABEL_F_QUICK;
	else
		label->flags |= DASD_ESE_LABEL_F_FULL;
	label->blksize = blksize;
	label->format_tod = get_tod_clock();
	strscpy(label->kernel_version, init_utsname()->release,
		sizeof(label->kernel_version));

	/*
	 * Populate the cache directly from the bytes just computed instead of
	 * synchronously reading them back from disk after the write lands.
	 */
	private->ese_label = *label;
	private->ese_label_valid = true;
}

static struct dasd_ccw_req *
dasd_eckd_build_format(struct dasd_device *base, struct dasd_device *startdev,
		       struct format_data_t *fdata, int enable_pav)
{
	struct dasd_eckd_private *base_priv;
	struct dasd_eckd_private *start_priv;
	struct dasd_ccw_req *fcp;
	struct eckd_count *ect;
	struct ch_t address;
	struct ccw1 *ccw;
	void *data;
	int rpt;
	int cplength, datasize;
	int i, j;
	int intensity = 0;
	int r0_perm;
	int nr_tracks;
	int use_prefix;
	int write_label;

	if (enable_pav)
		startdev = dasd_alias_get_start_dev(base);

	if (!startdev)
		startdev = base;

	start_priv = startdev->private;
	base_priv = base->private;

	rpt = recs_per_track(&base_priv->rdc_data, 0, fdata->blksize);

	nr_tracks = fdata->stop_unit - fdata->start_unit + 1;

	/*
	 * fdata->intensity is a bit string that tells us what to do:
	 *   Bit 0: write record zero
	 *   Bit 1: write home address, currently not supported
	 *   Bit 2: invalidate tracks
	 *   Bit 3: use OS/390 compatible disk layout (cdl)
	 *   Bit 4: do not allow storage subsystem to modify record zero
	 * Only some bit combinations do make sense.
	 */
	if (fdata->intensity & 0x10) {
		r0_perm = 0;
		intensity = fdata->intensity & ~0x10;
	} else {
		r0_perm = 1;
		intensity = fdata->intensity;
	}

	use_prefix = base_priv->features.feature[8] & 0x01;

	/*
	 * Stamp the format label into R4 of the very first track. Only for CDL
	 * (R4 is the first non-special record there), only when this request
	 * covers track 0, only for the record-writing format intensities (not
	 * track invalidation), and only if the track actually has an R4.
	 */
	write_label = (intensity & 0x08) && !((intensity & ~0x08) & 0x04) &&
		      fdata->start_unit == 0 && rpt > 3;

	switch (intensity) {
	case 0x00:	/* Normal format */
	case 0x08:	/* Normal format, use cdl. */
		cplength = 2 + (rpt*nr_tracks);
		if (use_prefix)
			datasize = sizeof(struct PFX_eckd_data) +
				sizeof(struct LO_eckd_data) +
				rpt * nr_tracks * sizeof(struct eckd_count);
		else
			datasize = sizeof(struct DE_eckd_data) +
				sizeof(struct LO_eckd_data) +
				rpt * nr_tracks * sizeof(struct eckd_count);
		break;
	case 0x01:	/* Write record zero and format track. */
	case 0x09:	/* Write record zero and format track, use cdl. */
		cplength = 2 + rpt * nr_tracks;
		if (use_prefix)
			datasize = sizeof(struct PFX_eckd_data) +
				sizeof(struct LO_eckd_data) +
				sizeof(struct eckd_count) +
				rpt * nr_tracks * sizeof(struct eckd_count);
		else
			datasize = sizeof(struct DE_eckd_data) +
				sizeof(struct LO_eckd_data) +
				sizeof(struct eckd_count) +
				rpt * nr_tracks * sizeof(struct eckd_count);
		break;
	case 0x04:	/* Invalidate track. */
	case 0x0c:	/* Invalidate track, use cdl. */
		cplength = 3;
		if (use_prefix)
			datasize = sizeof(struct PFX_eckd_data) +
				sizeof(struct LO_eckd_data) +
				sizeof(struct eckd_count);
		else
			datasize = sizeof(struct DE_eckd_data) +
				sizeof(struct LO_eckd_data) +
				sizeof(struct eckd_count);
		break;
	default:
		dev_warn(&startdev->cdev->dev,
			 "An I/O control call used incorrect flags 0x%x\n",
			 fdata->intensity);
		return ERR_PTR(-EINVAL);
	}

	/* room for the label data that R4 carries in addition to its count */
	if (write_label)
		datasize += fdata->blksize;

	fcp = dasd_fmalloc_request(DASD_ECKD_MAGIC, cplength, datasize, startdev);
	if (IS_ERR(fcp))
		return fcp;

	start_priv->count++;
	data = fcp->data;
	ccw = fcp->cpaddr;

	switch (intensity & ~0x08) {
	case 0x00: /* Normal format. */
		if (use_prefix) {
			prefix(ccw++, (struct PFX_eckd_data *) data,
			       fdata->start_unit, fdata->stop_unit,
			       DASD_ECKD_CCW_WRITE_CKD, base, startdev);
			/* grant subsystem permission to format R0 */
			if (r0_perm)
				((struct PFX_eckd_data *)data)
					->define_extent.ga_extended |= 0x04;
			data += sizeof(struct PFX_eckd_data);
		} else {
			define_extent(ccw++, (struct DE_eckd_data *) data,
				      fdata->start_unit, fdata->stop_unit,
				      DASD_ECKD_CCW_WRITE_CKD, startdev, 0);
			/* grant subsystem permission to format R0 */
			if (r0_perm)
				((struct DE_eckd_data *) data)
					->ga_extended |= 0x04;
			data += sizeof(struct DE_eckd_data);
		}
		ccw[-1].flags |= CCW_FLAG_CC;
		locate_record(ccw++, (struct LO_eckd_data *) data,
			      fdata->start_unit, 0, rpt*nr_tracks,
			      DASD_ECKD_CCW_WRITE_CKD, base,
			      fdata->blksize);
		data += sizeof(struct LO_eckd_data);
		break;
	case 0x01: /* Write record zero + format track. */
		if (use_prefix) {
			prefix(ccw++, (struct PFX_eckd_data *) data,
			       fdata->start_unit, fdata->stop_unit,
			       DASD_ECKD_CCW_WRITE_RECORD_ZERO,
			       base, startdev);
			data += sizeof(struct PFX_eckd_data);
		} else {
			define_extent(ccw++, (struct DE_eckd_data *) data,
			       fdata->start_unit, fdata->stop_unit,
			       DASD_ECKD_CCW_WRITE_RECORD_ZERO, startdev, 0);
			data += sizeof(struct DE_eckd_data);
		}
		ccw[-1].flags |= CCW_FLAG_CC;
		locate_record(ccw++, (struct LO_eckd_data *) data,
			      fdata->start_unit, 0, rpt * nr_tracks + 1,
			      DASD_ECKD_CCW_WRITE_RECORD_ZERO, base,
			      base->block->bp_block);
		data += sizeof(struct LO_eckd_data);
		break;
	case 0x04: /* Invalidate track. */
		if (use_prefix) {
			prefix(ccw++, (struct PFX_eckd_data *) data,
			       fdata->start_unit, fdata->stop_unit,
			       DASD_ECKD_CCW_WRITE_CKD, base, startdev);
			data += sizeof(struct PFX_eckd_data);
		} else {
			define_extent(ccw++, (struct DE_eckd_data *) data,
			       fdata->start_unit, fdata->stop_unit,
			       DASD_ECKD_CCW_WRITE_CKD, startdev, 0);
			data += sizeof(struct DE_eckd_data);
		}
		ccw[-1].flags |= CCW_FLAG_CC;
		locate_record(ccw++, (struct LO_eckd_data *) data,
			      fdata->start_unit, 0, 1,
			      DASD_ECKD_CCW_WRITE_CKD, base, 8);
		data += sizeof(struct LO_eckd_data);
		break;
	}

	for (j = 0; j < nr_tracks; j++) {
		/* calculate cylinder and head for the current track */
		set_ch_t(&address,
			 (fdata->start_unit + j) /
			 base_priv->rdc_data.trk_per_cyl,
			 (fdata->start_unit + j) %
			 base_priv->rdc_data.trk_per_cyl);
		if (intensity & 0x01) {	/* write record zero */
			ect = (struct eckd_count *) data;
			data += sizeof(struct eckd_count);
			ect->cyl = address.cyl;
			ect->head = address.head;
			ect->record = 0;
			ect->kl = 0;
			ect->dl = 8;
			ccw[-1].flags |= CCW_FLAG_CC;
			ccw->cmd_code = DASD_ECKD_CCW_WRITE_RECORD_ZERO;
			ccw->flags = CCW_FLAG_SLI;
			ccw->count = 8;
			ccw->cda = virt_to_dma32(ect);
			ccw++;
		}
		if ((intensity & ~0x08) & 0x04) {	/* erase track */
			ect = (struct eckd_count *) data;
			data += sizeof(struct eckd_count);
			ect->cyl = address.cyl;
			ect->head = address.head;
			ect->record = 1;
			ect->kl = 0;
			ect->dl = 0;
			ccw[-1].flags |= CCW_FLAG_CC;
			ccw->cmd_code = DASD_ECKD_CCW_WRITE_CKD;
			ccw->flags = CCW_FLAG_SLI;
			ccw->count = 8;
			ccw->cda = virt_to_dma32(ect);
		} else {		/* write remaining records */
			for (i = 0; i < rpt; i++) {
				ect = (struct eckd_count *) data;
				data += sizeof(struct eckd_count);
				ect->cyl = address.cyl;
				ect->head = address.head;
				ect->record = i + 1;
				ect->kl = 0;
				ect->dl = fdata->blksize;
				/*
				 * Check for special tracks 0-1
				 * when formatting CDL
				 */
				if ((intensity & 0x08) &&
				    address.cyl == 0 && address.head == 0) {
					if (i < 3) {
						ect->kl = 4;
						ect->dl = sizes_trk0[i] - 4;
					}
				}
				if ((intensity & 0x08) &&
				    address.cyl == 0 && address.head == 1) {
					ect->kl = 44;
					ect->dl = LABEL_SIZE - 44;
				}
				ccw[-1].flags |= CCW_FLAG_CC;
				if (i != 0 || j == 0)
					ccw->cmd_code =
						DASD_ECKD_CCW_WRITE_CKD;
				else
					ccw->cmd_code =
						DASD_ECKD_CCW_WRITE_CKD_MT;
				ccw->flags = CCW_FLAG_SLI;
				if (write_label && address.cyl == 0 &&
				    address.head == 0 && i == 3) {
					/*
					 * R4 carries the label as its record
					 * data; it follows ect contiguously so
					 * the CCW transfers count + data.
					 */
					dasd_eckd_fill_format_label(base,
								    data,
								    fdata->blksize);
					data += fdata->blksize;
					ccw->count = 8 + fdata->blksize;
				} else {
					ccw->count = 8;
				}
				ccw->cda = virt_to_dma32(ect);
				ccw++;
			}
		}
	}

	fcp->startdev = startdev;
	fcp->memdev = startdev;
	fcp->basedev = base;
	fcp->retries = 256;
	fcp->expires = startdev->default_expires * HZ;
	fcp->buildclk = get_tod_clock();
	fcp->status = DASD_CQR_FILLED;

	return fcp;
}

/*
 * Wrapper function to build a CCW request depending on input data
 */
static struct dasd_ccw_req *
dasd_eckd_format_build_ccw_req(struct dasd_device *base,
			       struct format_data_t *fdata, int enable_pav,
			       int tpm, struct eckd_count *fmt_buffer, int rpt)
{
	struct dasd_ccw_req *ccw_req;

	if (!fmt_buffer) {
		ccw_req = dasd_eckd_build_format(base, NULL, fdata, enable_pav);
	} else {
		if (tpm)
			ccw_req = dasd_eckd_build_check_tcw(base, fdata,
							    enable_pav,
							    fmt_buffer, rpt);
		else
			ccw_req = dasd_eckd_build_check(base, fdata, enable_pav,
							fmt_buffer, rpt);
	}

	return ccw_req;
}

/*
 * Sanity checks on format_data
 */
static int dasd_eckd_format_sanity_checks(struct dasd_device *base,
					  struct format_data_t *fdata)
{
	struct dasd_eckd_private *private = base->private;

	if (fdata->start_unit >=
	    (private->real_cyl * private->rdc_data.trk_per_cyl)) {
		dev_warn(&base->cdev->dev,
			 "Start track number %u used in formatting is too big\n",
			 fdata->start_unit);
		return -EINVAL;
	}
	if (fdata->stop_unit >=
	    (private->real_cyl * private->rdc_data.trk_per_cyl)) {
		dev_warn(&base->cdev->dev,
			 "Stop track number %u used in formatting is too big\n",
			 fdata->stop_unit);
		return -EINVAL;
	}
	if (fdata->start_unit > fdata->stop_unit) {
		dev_warn(&base->cdev->dev,
			 "Start track %u used in formatting exceeds end track\n",
			 fdata->start_unit);
		return -EINVAL;
	}
	if (dasd_check_blocksize(fdata->blksize) != 0) {
		dev_warn(&base->cdev->dev,
			 "The DASD cannot be formatted with block size %u\n",
			 fdata->blksize);
		return -EINVAL;
	}
	return 0;
}

/*
 * This function will process format_data originally coming from an IOCTL
 */
static int dasd_eckd_format_process_data(struct dasd_device *base,
					 struct format_data_t *fdata,
					 int enable_pav, int tpm,
					 struct eckd_count *fmt_buffer, int rpt,
					 struct irb *irb)
{
	struct dasd_eckd_private *private = base->private;
	struct dasd_ccw_req *cqr, *n;
	struct list_head format_queue;
	struct dasd_device *device;
	char *sense = NULL;
	int old_start, old_stop, format_step;
	int step, retry;
	int rc;

	rc = dasd_eckd_format_sanity_checks(base, fdata);
	if (rc)
		return rc;

	INIT_LIST_HEAD(&format_queue);

	old_start = fdata->start_unit;
	old_stop = fdata->stop_unit;

	if (!tpm && fmt_buffer != NULL) {
		/* Command Mode / Format Check */
		format_step = 1;
	} else if (tpm && fmt_buffer != NULL) {
		/* Transport Mode / Format Check */
		format_step = DASD_CQR_MAX_CCW / rpt;
	} else {
		/* Normal Formatting */
		format_step = DASD_CQR_MAX_CCW /
			recs_per_track(&private->rdc_data, 0, fdata->blksize);
	}

	do {
		retry = 0;
		while (fdata->start_unit <= old_stop) {
			step = fdata->stop_unit - fdata->start_unit + 1;
			if (step > format_step) {
				fdata->stop_unit =
					fdata->start_unit + format_step - 1;
			}

			cqr = dasd_eckd_format_build_ccw_req(base, fdata,
							     enable_pav, tpm,
							     fmt_buffer, rpt);
			if (IS_ERR(cqr)) {
				rc = PTR_ERR(cqr);
				if (rc == -ENOMEM) {
					if (list_empty(&format_queue))
						goto out;
					/*
					 * not enough memory available, start
					 * requests retry after first requests
					 * were finished
					 */
					retry = 1;
					break;
				}
				goto out_err;
			}
			list_add_tail(&cqr->blocklist, &format_queue);

			if (fmt_buffer) {
				step = fdata->stop_unit - fdata->start_unit + 1;
				fmt_buffer += rpt * step;
			}
			fdata->start_unit = fdata->stop_unit + 1;
			fdata->stop_unit = old_stop;
		}

		rc = dasd_sleep_on_queue(&format_queue);

out_err:
		list_for_each_entry_safe(cqr, n, &format_queue, blocklist) {
			device = cqr->startdev;
			private = device->private;

			if (cqr->status == DASD_CQR_FAILED) {
				/*
				 * Only get sense data if called by format
				 * check
				 */
				if (fmt_buffer && irb) {
					sense = dasd_get_sense(&cqr->irb);
					memcpy(irb, &cqr->irb, sizeof(*irb));
				}
				rc = -EIO;
			}
			list_del_init(&cqr->blocklist);
			dasd_ffree_request(cqr, device);
			private->count--;
		}

		if (rc && rc != -EIO)
			goto out;
		if (rc == -EIO) {
			/*
			 * In case fewer than the expected records are on the
			 * track, we will most likely get a 'No Record Found'
			 * error (in command mode) or a 'File Protected' error
			 * (in transport mode). Those particular cases shouldn't
			 * pass the -EIO to the IOCTL, therefore reset the rc
			 * and continue.
			 */
			if (sense &&
			    (sense[1] & SNS1_NO_REC_FOUND ||
			     sense[1] & SNS1_FILE_PROTECTED))
				retry = 1;
			else
				goto out;
		}

	} while (retry);

out:
	fdata->start_unit = old_start;
	fdata->stop_unit = old_stop;

	return rc;
}

static int dasd_eckd_format_device(struct dasd_device *base,
				   struct format_data_t *fdata, int enable_pav)
{
	struct dasd_eckd_private *private = base->private;
	int rc;

	rc = dasd_eckd_format_process_data(base, fdata, enable_pav, 0, NULL,
					   0, NULL);
	if (fdata->start_unit != 0)
		return rc;

	if (rc) {
		/*
		 * The format failed, so the label cached speculatively during
		 * CCW build may not match the disk; drop it so is_ese() falls
		 * back to the hardware field until the next successful format
		 * or bring-up.
		 */
		private->ese_label_valid = false;
		return rc;
	}

	/*
	 * The quick-format indicator was consumed by the label stamped into
	 * track 0; clear it so a later format that is not preceded by a full
	 * space release is recorded as a full format.
	 */
	private->ese_format_quick = 0;

	/*
	 * A full format returns the device to a fully sparse state and has just
	 * committed a fresh label; restart the heuristic from ft1 on the now
	 * current is_ese state, without an offline cycle.
	 */
	dasd_ft_bias_apply(base);

	return rc;
}

static bool test_and_set_format_track(sector_t start, sector_t end,
				      struct dasd_ccw_req *cqr,
				      struct dasd_block *block,
				      struct dasd_device *device,
				      struct dasd_format_entry **entry)
{
	struct dasd_format_entry *to_format, *format;
	unsigned long flags;
	bool rc = false;
	int i = 0;

	/* marked as a collision by dasd_return_cqr_cb last round: retry */
	if (cqr && READ_ONCE(cqr->collision)) {
		WRITE_ONCE(cqr->collision, false);
		return true;
	}
	spin_lock_irqsave(&block->format_lock, flags);
	while (i < DASD_NR_FORMAT_ENTRIES &&
	       READ_ONCE(device->format_entry[i].cqr))
		i++;

	if (i >= DASD_NR_FORMAT_ENTRIES) {
		rc = true;
		goto out;
	}

	list_for_each_entry(format, &block->format_list, list) {
		if (!(end < format->start_trk || format->end_trk < start)) {
			rc = true;
			goto out;
		}
	}
	to_format = &device->format_entry[i];
	to_format->start_trk = start;
	to_format->end_trk = end;
	to_format->cqr = cqr;
	list_add_tail(&to_format->list, &block->format_list);
	*entry = to_format;

out:
	spin_unlock_irqrestore(&block->format_lock, flags);
	return rc;
}

static void clear_format_track(struct dasd_format_entry *format,
			       struct dasd_block *block)
{
	unsigned long flags;

	spin_lock_irqsave(&block->format_lock, flags);
	list_del_init(&format->list);
	format->cqr = NULL;
	spin_unlock_irqrestore(&block->format_lock, flags);
}

/*
 * Adaptive ft_bias heuristic, called once per IO from dasd_eckd_build_cp().
 * Probes the device formatting state by briefly switching to ft0 and measuring
 * the NRF rate; parameters are derived from ft_bias.
 */
static void dasd_ese_heuristic_tick(struct dasd_device *basedev)
{
	int ios, nrf, rate;

	if (atomic_inc_return(&basedev->ese_io_cnt) < (int)basedev->ese_probe_interval)
		return;

	/*
	 * One wins the race to evaluate, the rest see ios == 0 after the
	 * xchg and return early, preventing redundant state transitions.
	 */
	ios = atomic_xchg(&basedev->ese_io_cnt, 0);
	if (ios <= 0)
		return;

	switch (basedev->ese_probe_state) {
	case DASD_ESE_HEU_FT1_ACTIVE:
		/* Start ft0 probe window, reset NRF counter for clean measurement */
		basedev->fulltrack          = 0;
		basedev->ese_probe_state    = DASD_ESE_HEU_PROBING;
		basedev->ese_probe_interval = basedev->ese_heu_probe_window;
		atomic_set(&basedev->ese_nrf_window, 0);
		break;

	case DASD_ESE_HEU_PROBING:
	case DASD_ESE_HEU_FT0_STABLE:
		nrf  = atomic_xchg(&basedev->ese_nrf_window, 0);
		rate = (int)((u64)nrf * 1000 / ios);
		if (rate > (int)basedev->ese_heu_nrf_high) {
			/* NRF rate high: device still sparse, ft1 is better */
			basedev->fulltrack          = 1;
			basedev->ese_probe_state    = DASD_ESE_HEU_FT1_ACTIVE;
			basedev->ese_probe_interval = basedev->ese_heu_start_interval;
		} else if (basedev->ese_probe_state == DASD_ESE_HEU_PROBING) {
			/*
			 * NRF rate low: device mostly formatted, ft0 is faster.
			 * Re-probe frequently at first, then back off below.
			 */
			basedev->fulltrack          = 0;
			basedev->ese_probe_state    = DASD_ESE_HEU_FT0_STABLE;
			basedev->ese_probe_interval = basedev->ese_heu_probe_window;
		} else {
			/*
			 * Still stable in ft0: re-assert plain-write mode so a
			 * fulltrack value left behind by a racing sysfs write
			 * self-corrects, and back off the re-probe interval
			 * (double it, capped at max_interval) so a long-lived
			 * formatted device is not probed more often than needed.
			 */
			basedev->fulltrack          = 0;
			basedev->ese_probe_interval =
				min(basedev->ese_probe_interval * 2,
				    basedev->ese_heu_max_interval);
		}
		break;
	}
}

static void dasd_eckd_ese_format(struct dasd_device *startdev, struct dasd_ccw_req *cqr,
				 struct irb *irb)
{
	struct dasd_format_entry *format = NULL;
	unsigned int first_offs, last_offs;
	struct dasd_eckd_private *private;
	struct dasd_ccw_req *base_cqr;
	sector_t first_rec, last_rec;
	sector_t first_trk, last_trk;
	unsigned int proc_bytes = 0;
	struct dasd_ccw_req *fcqr;
	unsigned int recs_per_trk;
	struct dasd_device *base;
	struct dasd_block *block;
	unsigned int blksize;
	struct request *req;
	sector_t curr_trk;
	unsigned int diff;
	int rc;

	req = dasd_get_callback_data(cqr);
	block = cqr->block;
	base = block->base;
	private = base->private;
	if (dasd_ese_adaptive(base))
		atomic_inc(&base->ese_nrf_window);
	blksize = block->bp_block;
	recs_per_trk = recs_per_track(&private->rdc_data, 0, blksize);

	/* Calculate record id of first and last block. */
	first_rec = blk_rq_pos(req) >> block->s2b_shift;
	first_trk = first_rec;
	first_offs = sector_div(first_trk, recs_per_trk);
	last_rec = (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
	last_trk = last_rec;
	last_offs = sector_div(last_trk, recs_per_trk);

	/*
	 * detect if some data has already been processed and the unformatted track is
	 * within the request.
	 * If so, finish the request first with the already processed bytes and let the
	 * blocklayer only redrive unformatted part.
	 * With this we ensure that there is no overlap of existing data with unformatted
	 * zero blocks
	 */
	rc = dasd_eckd_track_from_irb(irb, base, &curr_trk);
	if (rc) {
		/* sense data could not be parsed - this will not resolve by retrying */
		cqr->status = DASD_CQR_ERROR;
		goto out;
	}
	if (curr_trk >= (sector_t)private->real_cyl * private->rdc_data.trk_per_cyl) {
		DBF_DEV_EVENT(DBF_WARNING, startdev,
			      "ESE error track %llu exceeds device geometry\n",
			      curr_trk);
		cqr->status = DASD_CQR_ERROR;
		goto out;
	}
	if (curr_trk < first_trk || curr_trk > last_trk) {
		DBF_DEV_EVENT(DBF_WARNING, startdev,
			      "ESE error track %llu not within range %llu - %llu\n",
			      curr_trk, first_trk, last_trk);
		cqr->status = DASD_CQR_ERROR;
		goto out;
	}
	if (curr_trk != first_trk) {
		proc_bytes = ((curr_trk - first_trk) * recs_per_trk - first_offs) * blksize;
		cqr->proc_bytes = proc_bytes;
		cqr->status = DASD_CQR_SUCCESS;
		cqr->stopclk = get_tod_clock();
		goto out;
	}

	/*
	 * If there are multiple tracks to be format-written, we can not write
	 * the partial last track since we do not know if it is already formatted
	 * or not so skip the partial last track for now. Return the partial
	 * completion to blocklayer and let it redo the remainder
	 */
	if (first_trk != last_trk && last_offs + 1 < recs_per_trk) {
		diff = last_offs + 1;
		last_rec = last_rec - diff;
		last_trk = last_rec;
		last_offs = sector_div(last_trk, recs_per_trk);
		proc_bytes = (last_rec - first_rec + 1) * blksize;
	}
	if (first_offs > 0 || last_offs + 1 < recs_per_trk) {
		/* test if tracks are already in formatting by another thread */
		if (test_and_set_format_track(first_trk, last_trk, cqr,
					      cqr->block, cqr->startdev, &format)) {
			/* this is no real error so do not count down retries */
			cqr->retries++;
			goto out_retry;
		}
	}

	fcqr = dasd_eckd_build_cp_tpm_writefulltrack(startdev, block, req,
						     first_rec, last_rec,
						     first_trk, last_trk,
						     first_offs, last_offs,
						     recs_per_trk, blksize, cqr);
	if (IS_ERR(fcqr)) {
		if (format)
			clear_format_track(format, cqr->block);
		if (PTR_ERR(fcqr) == -EINVAL) {
			/* permanent build failure - fail instead of retrying */
			cqr->status = DASD_CQR_ERROR;
			goto out;
		}
		/*
		 * Transient conditions - the XRC clock is not in sync (-EAGAIN)
		 * or the format request pool is momentarily exhausted under load
		 * (-ENOMEM). Retry the origin without counting down its retries.
		 */
		if (PTR_ERR(fcqr) == -EAGAIN || PTR_ERR(fcqr) == -ENOMEM)
			cqr->retries++;
		goto out_retry;
	}

	if (format) {
		/* occupancy marker; the free-slot scan reads it with READ_ONCE */
		WRITE_ONCE(format->cqr, fcqr);
		fcqr->format = format;
	}

	/*
	 * cqr may be an ERP request; dq and the owning request are only set on
	 * the base request at the end of the ERP chain, so copy from there.
	 */
	base_cqr = cqr;
	while (base_cqr->refers)
		base_cqr = base_cqr->refers;
	fcqr->dq = base_cqr->dq;
	fcqr->callback_data = base_cqr->callback_data;
	if (proc_bytes)
		fcqr->proc_bytes = proc_bytes;
	fcqr->status = DASD_CQR_FILLED;
	((struct dasd_eckd_private *)fcqr->memdev->private)->count++;
	/*
	 * stage under ese_lock; dasd_block_tasklet splices it into ccw_queue.
	 * Direct enqueue here would invert queue_lock / ccwdev_lock.
	 */
	spin_lock(&block->ese_lock);
	list_add(&fcqr->blocklist, &block->ese_staging);
	spin_unlock(&block->ese_lock);
	/* mark origin CQR as aborted; ccwdev_lock is held by the IRQ handler */
	cqr->status = DASD_CQR_ABORT;
	goto out;

out_retry:
	/*
	 * If we can't format now, let the request go
	 * one extra round. Maybe we can format later.
	 * re-queue at the end to let potential format collision finish first
	 */
	list_move_tail(&cqr->devlist, &cqr->startdev->ccw_queue);
	cqr->status = DASD_CQR_QUEUED;
out:
	dasd_device_clear_timer(startdev);
	dasd_schedule_block_bh(block);
	dasd_schedule_device_bh(startdev);
	return;
}

/*
 * When data is read from an unformatted area of an ESE volume, this function
 * returns zeroed data and thereby mimics a read of zero data.
 *
 * The first unformatted track is the one that got the NRF error, the address is
 * encoded in the sense data.
 *
 * All tracks before have returned valid data and should not be touched.
 * All tracks after the unformatted track might be formatted or not. This is
 * currently not known, remember the processed data and return the remainder of
 * the request to the blocklayer in __dasd_cleanup_cqr().
 */
static int dasd_eckd_ese_read(struct dasd_ccw_req *cqr, struct irb *irb)
{
	struct dasd_eckd_private *private;
	sector_t first_trk, last_trk;
	sector_t first_blk, last_blk;
	unsigned int blksize, off;
	unsigned int recs_per_trk;
	struct dasd_device *base;
	struct req_iterator iter;
	struct dasd_block *block;
	unsigned int skip_block;
	unsigned int blk_count;
	struct request *req;
	struct bio_vec bv;
	sector_t curr_trk;
	sector_t end_blk;
	char *dst;
	int rc;

	req = (struct request *) cqr->callback_data;
	base = cqr->block->base;
	blksize = base->block->bp_block;
	block =  cqr->block;
	private = base->private;
	skip_block = 0;
	blk_count = 0;

	recs_per_trk = recs_per_track(&private->rdc_data, 0, blksize);
	first_trk = first_blk = blk_rq_pos(req) >> block->s2b_shift;
	sector_div(first_trk, recs_per_trk);
	last_trk = last_blk =
		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
	sector_div(last_trk, recs_per_trk);
	rc = dasd_eckd_track_from_irb(irb, base, &curr_trk);
	if (rc)
		return rc;

	/* sanity check if the current track from sense data is valid */
	if (curr_trk < first_trk || curr_trk > last_trk) {
		DBF_DEV_EVENT(DBF_WARNING, base,
			      "ESE error track %llu not within range %llu - %llu\n",
			      curr_trk, first_trk, last_trk);
		return -EINVAL;
	}

	/*
	 * if not the first track got the NRF error we have to skip over valid
	 * blocks
	 */
	if (curr_trk != first_trk)
		skip_block = curr_trk * recs_per_trk - first_blk;

	/* we have no information beyond the current track */
	end_blk = (curr_trk + 1) * recs_per_trk;

	rq_for_each_segment(bv, req, iter) {
		dst = bvec_virt(&bv);
		for (off = 0; off < bv.bv_len; off += blksize) {
			if (first_blk + blk_count >= end_blk) {
				cqr->proc_bytes = blk_count * blksize;
				return 0;
			}
			if (dst && !skip_block)
				memset(dst, 0, blksize);
			else
				skip_block--;
			dst += blksize;
			blk_count++;
		}
	}
	return 0;
}

/*
 * Helper function to count consecutive records of a single track.
 */
static int dasd_eckd_count_records(struct eckd_count *fmt_buffer, int start,
				   int max)
{
	int head;
	int i;

	head = fmt_buffer[start].head;

	/*
	 * There are 3 conditions where we stop counting:
	 * - if data reoccurs (same head and record may reoccur), which may
	 *   happen due to the way DASD_ECKD_CCW_READ_COUNT works
	 * - when the head changes, because we're iterating over several tracks
	 *   then (DASD_ECKD_CCW_READ_COUNT_MT)
	 * - when we've reached the end of sensible data in the buffer (the
	 *   record will be 0 then)
	 */
	for (i = start; i < max; i++) {
		if (i > start) {
			if ((fmt_buffer[i].head == head &&
			    fmt_buffer[i].record == 1) ||
			    fmt_buffer[i].head != head ||
			    fmt_buffer[i].record == 0)
				break;
		}
	}

	return i - start;
}

/*
 * Evaluate a given range of tracks. Data like number of records, blocksize,
 * record ids, and key length are compared with expected data.
 *
 * If a mismatch occurs, the corresponding error bit is set, as well as
 * additional information, depending on the error.
 */
static void dasd_eckd_format_evaluate_tracks(struct eckd_count *fmt_buffer,
					     struct format_check_t *cdata,
					     int rpt_max, int rpt_exp,
					     int trk_per_cyl, int tpm)
{
	struct ch_t geo;
	int max_entries;
	int count = 0;
	int trkcount;
	int blksize;
	int pos = 0;
	int i, j;
	int kl;

	trkcount = cdata->expect.stop_unit - cdata->expect.start_unit + 1;
	max_entries = trkcount * rpt_max;

	for (i = cdata->expect.start_unit; i <= cdata->expect.stop_unit; i++) {
		/* Calculate the correct next starting position in the buffer */
		if (tpm) {
			while (fmt_buffer[pos].record == 0 &&
			       fmt_buffer[pos].dl == 0) {
				if (pos++ > max_entries)
					break;
			}
		} else {
			if (i != cdata->expect.start_unit)
				pos += rpt_max - count;
		}

		/* Calculate the expected geo values for the current track */
		set_ch_t(&geo, i / trk_per_cyl, i % trk_per_cyl);

		/* Count and check number of records */
		count = dasd_eckd_count_records(fmt_buffer, pos, pos + rpt_max);

		if (count < rpt_exp) {
			cdata->result = DASD_FMT_ERR_TOO_FEW_RECORDS;
			break;
		}
		if (count > rpt_exp) {
			cdata->result = DASD_FMT_ERR_TOO_MANY_RECORDS;
			break;
		}

		for (j = 0; j < count; j++, pos++) {
			blksize = cdata->expect.blksize;
			kl = 0;

			/*
			 * Set special values when checking CDL formatted
			 * devices.
			 */
			if ((cdata->expect.intensity & 0x08) &&
			    geo.cyl == 0 && geo.head == 0) {
				if (j < 3) {
					blksize = sizes_trk0[j] - 4;
					kl = 4;
				}
			}
			if ((cdata->expect.intensity & 0x08) &&
			    geo.cyl == 0 && geo.head == 1) {
				blksize = LABEL_SIZE - 44;
				kl = 44;
			}

			/* Check blocksize */
			if (fmt_buffer[pos].dl != blksize) {
				cdata->result = DASD_FMT_ERR_BLKSIZE;
				goto out;
			}
			/* Check if key length is 0 */
			if (fmt_buffer[pos].kl != kl) {
				cdata->result = DASD_FMT_ERR_KEY_LENGTH;
				goto out;
			}
			/* Check if record_id is correct */
			if (fmt_buffer[pos].cyl != geo.cyl ||
			    fmt_buffer[pos].head != geo.head ||
			    fmt_buffer[pos].record != (j + 1)) {
				cdata->result = DASD_FMT_ERR_RECORD_ID;
				goto out;
			}
		}
	}

out:
	/*
	 * In case of no errors, we need to decrease by one
	 * to get the correct positions.
	 */
	if (!cdata->result) {
		i--;
		pos--;
	}

	cdata->unit = i;
	cdata->num_records = count;
	cdata->rec = fmt_buffer[pos].record;
	cdata->blksize = fmt_buffer[pos].dl;
	cdata->key_length = fmt_buffer[pos].kl;
}

/*
 * Check the format of a range of tracks of a DASD.
 */
static int dasd_eckd_check_device_format(struct dasd_device *base,
					 struct format_check_t *cdata,
					 int enable_pav)
{
	struct dasd_eckd_private *private = base->private;
	struct eckd_count *fmt_buffer;
	size_t fmt_buffer_size;
	unsigned int trkcount;
	int rpt_max, rpt_exp;
	struct irb irb;
	int trk_per_cyl;
	int tpm = 0;
	int rc;

	trk_per_cyl = private->rdc_data.trk_per_cyl;

	/* Get maximum and expected amount of records per track */
	rpt_max = recs_per_track(&private->rdc_data, 0, 512) + 1;
	rpt_exp = recs_per_track(&private->rdc_data, 0, cdata->expect.blksize);

	trkcount = cdata->expect.stop_unit - cdata->expect.start_unit + 1;
	if (check_mul_overflow(trkcount, rpt_max, &fmt_buffer_size) ||
	    check_mul_overflow(fmt_buffer_size, sizeof(struct eckd_count), &fmt_buffer_size))
		return -EINVAL;

	fmt_buffer = kzalloc(fmt_buffer_size, GFP_KERNEL | GFP_DMA);
	if (!fmt_buffer)
		return -ENOMEM;

	/*
	 * A certain FICON feature subset is needed to operate in transport
	 * mode. Additionally, the support for transport mode is implicitly
	 * checked by comparing the buffer size with fcx_max_data. As long as
	 * the buffer size is smaller we can operate in transport mode and
	 * process multiple tracks. If not, only one track at once is being
	 * processed using command mode.
	 */
	if ((private->features.feature[40] & 0x04) &&
	    fmt_buffer_size <= private->fcx_max_data)
		tpm = 1;

	rc = dasd_eckd_format_process_data(base, &cdata->expect, enable_pav,
					   tpm, fmt_buffer, rpt_max, &irb);
	if (rc && rc != -EIO)
		goto out;
	if (rc == -EIO) {
		/*
		 * If our first attempt with transport mode enabled comes back
		 * with an incorrect length error, we're going to retry the
		 * check with command mode.
		 */
		if (tpm && scsw_cstat(&irb.scsw) == 0x40) {
			tpm = 0;
			rc = dasd_eckd_format_process_data(base, &cdata->expect,
							   enable_pav, tpm,
							   fmt_buffer, rpt_max,
							   &irb);
			if (rc)
				goto out;
		} else {
			goto out;
		}
	}

	dasd_eckd_format_evaluate_tracks(fmt_buffer, cdata, rpt_max, rpt_exp,
					 trk_per_cyl, tpm);

out:
	kfree(fmt_buffer);

	return rc;
}

static void dasd_eckd_handle_terminated_request(struct dasd_ccw_req *cqr)
{
	if (cqr->retries < 0) {
		cqr->status = DASD_CQR_FAILED;
		return;
	}
	cqr->status = DASD_CQR_FILLED;
	if (cqr->block && (cqr->startdev != cqr->block->base)) {
		dasd_eckd_reset_ccw_to_base_io(cqr);
		cqr->startdev = cqr->block->base;
		cqr->lpm = dasd_path_get_opm(cqr->block->base);
	}
};

static dasd_erp_fn_t
dasd_eckd_erp_action(struct dasd_ccw_req * cqr)
{
	struct dasd_device *device = (struct dasd_device *) cqr->startdev;
	struct ccw_device *cdev = device->cdev;

	switch (cdev->id.cu_type) {
	case 0x3990:
	case 0x2105:
	case 0x2107:
	case 0x1750:
		return dasd_3990_erp_action;
	case 0x9343:
	case 0x3880:
	default:
		return dasd_default_erp_action;
	}
}

static dasd_erp_fn_t
dasd_eckd_erp_postaction(struct dasd_ccw_req * cqr)
{
	return dasd_default_erp_postaction;
}

static void dasd_eckd_check_for_device_change(struct dasd_device *device,
					      struct dasd_ccw_req *cqr,
					      struct irb *irb)
{
	char mask;
	char *sense = NULL;
	struct dasd_eckd_private *private = device->private;

	/* first of all check for state change pending interrupt */
	mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
	if ((scsw_dstat(&irb->scsw) & mask) == mask) {
		/*
		 * for alias only, not in offline processing
		 * and only if not suspended
		 */
		if (!device->block && private->lcu &&
		    device->state == DASD_STATE_ONLINE &&
		    !test_bit(DASD_FLAG_OFFLINE, &device->flags) &&
		    !test_bit(DASD_FLAG_SUSPENDED, &device->flags)) {
			/* schedule worker to reload device */
			dasd_reload_device(device);
		}
		dasd_generic_handle_state_change(device);
		return;
	}

	sense = dasd_get_sense(irb);
	if (!sense)
		return;

	/* summary unit check */
	if ((sense[27] & DASD_SENSE_BIT_0) && (sense[7] == 0x0D) &&
	    (scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK)) {
		if (test_and_set_bit(DASD_FLAG_SUC, &device->flags)) {
			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
				      "eckd suc: device already notified");
			return;
		}
		sense = dasd_get_sense(irb);
		if (!sense) {
			DBF_DEV_EVENT(DBF_WARNING, device, "%s",
				      "eckd suc: no reason code available");
			clear_bit(DASD_FLAG_SUC, &device->flags);
			return;

		}
		private->suc_reason = sense[8];
		DBF_DEV_EVENT(DBF_NOTICE, device, "%s %x",
			      "eckd handle summary unit check: reason",
			      private->suc_reason);
		dasd_get_device(device);
		if (!schedule_work(&device->suc_work))
			dasd_put_device(device);

		return;
	}

	/* service information message SIM */
	if (!cqr && !(sense[27] & DASD_SENSE_BIT_0) &&
	    ((sense[6] & DASD_SIM_SENSE) == DASD_SIM_SENSE)) {
		dasd_3990_erp_handle_sim(device, sense);
		return;
	}

	/* loss of device reservation is handled via base devices only
	 * as alias devices may be used with several bases
	 */
	if (device->block && (sense[27] & DASD_SENSE_BIT_0) &&
	    (sense[7] == 0x3F) &&
	    (scsw_dstat(&irb->scsw) & DEV_STAT_UNIT_CHECK) &&
	    test_bit(DASD_FLAG_IS_RESERVED, &device->flags)) {
		if (device->features & DASD_FEATURE_FAILONSLCK)
			set_bit(DASD_FLAG_LOCK_STOLEN, &device->flags);
		clear_bit(DASD_FLAG_IS_RESERVED, &device->flags);
		dev_err(&device->cdev->dev,
			"The device reservation was lost\n");
	}
}

static int dasd_eckd_ras_sanity_checks(struct dasd_device *device,
				       unsigned int first_trk,
				       unsigned int last_trk)
{
	struct dasd_eckd_private *private = device->private;
	unsigned int trks_per_vol;
	int rc = 0;

	trks_per_vol = private->real_cyl * private->rdc_data.trk_per_cyl;

	if (first_trk >= trks_per_vol) {
		dev_warn(&device->cdev->dev,
			 "Start track number %u used in the space release command is too big\n",
			 first_trk);
		rc = -EINVAL;
	} else if (last_trk >= trks_per_vol) {
		dev_warn(&device->cdev->dev,
			 "Stop track number %u used in the space release command is too big\n",
			 last_trk);
		rc = -EINVAL;
	} else if (first_trk > last_trk) {
		dev_warn(&device->cdev->dev,
			 "Start track %u used in the space release command exceeds the end track\n",
			 first_trk);
		rc = -EINVAL;
	}
	return rc;
}

/*
 * Number of extents the track range [from, to] spans. Extent n covers tracks
 * [n * trks_per_ext, (n + 1) * trks_per_ext - 1], so the range touches the
 * extents from (from / trks_per_ext) to (to / trks_per_ext) inclusive.
 */
static int count_exts(unsigned int from, unsigned int to, int trks_per_ext)
{
	return to / trks_per_ext - from / trks_per_ext + 1;
}

static int dasd_in_copy_relation(struct dasd_device *device)
{
	struct dasd_pprc_data_sc4 *temp;
	int rc;

	if (!dasd_eckd_pprc_enabled(device))
		return 0;

	temp = kzalloc_obj(*temp);
	if (!temp)
		return -ENOMEM;

	rc = dasd_eckd_query_pprc_status(device, temp);
	if (!rc)
		rc = temp->dev_info[0].state;

	kfree(temp);
	return rc;
}

/*
 * Release allocated space for a given range or an entire volume.
 */
static struct dasd_ccw_req *
dasd_eckd_dso_ras(struct dasd_device *device, struct dasd_block *block,
		  struct request *req, unsigned int first_trk,
		  unsigned int last_trk, int by_extent)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_dso_ras_ext_range *ras_range;
	struct dasd_rssd_features *features;
	struct dasd_dso_ras_data *ras_data;
	u16 heads, beg_head, end_head;
	int cur_to_trk, cur_from_trk;
	struct dasd_ccw_req *cqr;
	u32 beg_cyl, end_cyl;
	int copy_relation;
	struct ccw1 *ccw;
	int trks_per_ext;
	size_t ras_size;
	size_t size;
	int nr_exts;
	void *rq;
	int i;

	if (dasd_eckd_ras_sanity_checks(device, first_trk, last_trk))
		return ERR_PTR(-EINVAL);

	/*
	 * The block-layer discard path (req != NULL) runs in atomic context, so
	 * it must not issue the sleeping copy-relation (PPRC) query. It also
	 * leaves guarantee_init off - discard does not promise zeroing anyway.
	 */
	copy_relation = 0;
	if (!req) {
		copy_relation = dasd_in_copy_relation(device);
		if (copy_relation < 0)
			return ERR_PTR(copy_relation);
	}

	rq = req ? blk_mq_rq_to_pdu(req) : NULL;

	features = &private->features;

	trks_per_ext = dasd_eckd_ext_size(device) * private->rdc_data.trk_per_cyl;
	nr_exts = 0;
	if (by_extent)
		nr_exts = count_exts(first_trk, last_trk, trks_per_ext);
	ras_size = sizeof(*ras_data);
	size = ras_size + (nr_exts * sizeof(*ras_range));

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, size, device, rq);
	if (IS_ERR(cqr)) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate RAS request");
		return cqr;
	}

	ras_data = cqr->data;
	memset(ras_data, 0, size);

	ras_data->order = DSO_ORDER_RAS;
	ras_data->flags.vol_type = 0; /* CKD volume */
	/* Release specified extents or entire volume */
	ras_data->op_flags.by_extent = by_extent;
	/*
	 * This bit guarantees initialisation of tracks within an extent that is
	 * not fully specified, but is only supported with a certain feature
	 * subset and for devices not in a copy relation.
	 */
	if (!req && features->feature[56] & 0x01 && !copy_relation)
		ras_data->op_flags.guarantee_init = 1;

	/* cached copies - conf.ned may be freed under us by the reload worker */
	ras_data->lss = READ_ONCE(private->ned_lss);
	ras_data->dev_addr = READ_ONCE(private->ned_ua);
	ras_data->nr_exts = nr_exts;

	if (by_extent) {
		heads = private->rdc_data.trk_per_cyl;
		cur_from_trk = first_trk;
		cur_to_trk = first_trk + trks_per_ext -
			(first_trk % trks_per_ext) - 1;
		if (cur_to_trk > last_trk)
			cur_to_trk = last_trk;
		ras_range = (struct dasd_dso_ras_ext_range *)(cqr->data + ras_size);

		for (i = 0; i < nr_exts; i++) {
			beg_cyl = cur_from_trk / heads;
			beg_head = cur_from_trk % heads;
			end_cyl = cur_to_trk / heads;
			end_head = cur_to_trk % heads;

			set_ch_t(&ras_range->beg_ext, beg_cyl, beg_head);
			set_ch_t(&ras_range->end_ext, end_cyl, end_head);

			cur_from_trk = cur_to_trk + 1;
			cur_to_trk = cur_from_trk + trks_per_ext - 1;
			if (cur_to_trk > last_trk)
				cur_to_trk = last_trk;
			ras_range++;
		}
	}

	ccw = cqr->cpaddr;
	ccw->cda = virt_to_dma32(cqr->data);
	ccw->cmd_code = DASD_ECKD_CCW_DSO;
	ccw->count = size;

	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = block;
	cqr->retries = 256;
	cqr->expires = device->default_expires * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	return cqr;
}

static int dasd_eckd_release_space_full(struct dasd_device *device)
{
	struct dasd_eckd_private *private;
	struct dasd_ccw_req *cqr;
	int rc;

	cqr = dasd_eckd_dso_ras(device, NULL, NULL, 0, 0, 0);
	if (IS_ERR(cqr))
		return PTR_ERR(cqr);

	rc = dasd_sleep_on_interruptible(cqr);

	if (!rc) {
		/*
		 * Releasing all space (RAS) wipes every track and the device is
		 * fully sparse again, so restart the heuristic from ft1.
		 */
		dasd_ft_bias_apply(device);
		/*
		 * A full release is what makes a subsequent format a quick
		 * (thin) one; remember it so the format label records that.
		 */
		private = device->private;
		private->ese_format_quick = 1;
	}

	dasd_sfree_request(cqr, cqr->memdev);

	return rc;
}

static int dasd_eckd_release_space_trks(struct dasd_device *device,
					unsigned int from, unsigned int to)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_block *block = device->block;
	struct dasd_ccw_req *cqr, *n;
	struct list_head ras_queue;
	unsigned int device_exts;
	int trks_per_ext;
	int stop, step;
	int cur_pos;
	int rc = 0;
	int retry;

	INIT_LIST_HEAD(&ras_queue);

	if (dasd_eckd_ext_size(device) == 0)
		return -EINVAL;

	device_exts = private->real_cyl / dasd_eckd_ext_size(device);
	trks_per_ext = dasd_eckd_ext_size(device) * private->rdc_data.trk_per_cyl;

	/* Make sure device limits are not exceeded */
	step = trks_per_ext * min(device_exts, DASD_ECKD_RAS_EXTS_MAX);
	cur_pos = from;

	do {
		retry = 0;
		while (cur_pos < to) {
			stop = cur_pos + step -
				((cur_pos + step) % trks_per_ext) - 1;
			if (stop > to)
				stop = to;

			cqr = dasd_eckd_dso_ras(device, NULL, NULL, cur_pos, stop, 1);
			if (IS_ERR(cqr)) {
				rc = PTR_ERR(cqr);
				if (rc == -ENOMEM) {
					if (list_empty(&ras_queue))
						goto out;
					retry = 1;
					break;
				}
				goto err_out;
			}

			spin_lock_irq(&block->queue_lock);
			list_add_tail(&cqr->blocklist, &ras_queue);
			spin_unlock_irq(&block->queue_lock);
			cur_pos = stop + 1;
		}

		rc = dasd_sleep_on_queue_interruptible(&ras_queue);

err_out:
		list_for_each_entry_safe(cqr, n, &ras_queue, blocklist) {
			device = cqr->startdev;
			private = device->private;

			spin_lock_irq(&block->queue_lock);
			list_del_init(&cqr->blocklist);
			spin_unlock_irq(&block->queue_lock);
			dasd_sfree_request(cqr, device);
			private->count--;
		}
	} while (retry);

out:
	return rc;
}

static int dasd_eckd_release_space(struct dasd_device *device,
				   struct format_data_t *rdata)
{
	/*
	 * Space release (and thus a quick format) requires real ESE hardware.
	 * is_ese() may be true from a copied label on non-ESE hardware, so gate
	 * on the hardware capability, not on is_ese().
	 */
	if (!dasd_eckd_ese_capable(device))
		return -EOPNOTSUPP;

	if (rdata->intensity & DASD_FMT_INT_ESE_FULL)
		return dasd_eckd_release_space_full(device);
	else if (rdata->intensity == 0)
		return dasd_eckd_release_space_trks(device, rdata->start_unit,
						    rdata->stop_unit);
	else
		return -EINVAL;
}

static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_single(
					       struct dasd_device *startdev,
					       struct dasd_block *block,
					       struct request *req,
					       sector_t first_rec,
					       sector_t last_rec,
					       sector_t first_trk,
					       sector_t last_trk,
					       unsigned int first_offs,
					       unsigned int last_offs,
					       unsigned int blk_per_trk,
					       unsigned int blksize)
{
	struct dasd_eckd_private *private;
	dma64_t *idaws;
	struct LO_eckd_data *LO_data;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	struct req_iterator iter;
	struct bio_vec bv;
	char *dst;
	unsigned int off;
	int count, cidaw, cplength, datasize;
	sector_t recid;
	unsigned char cmd, rcmd;
	int use_prefix;
	struct dasd_device *basedev;

	basedev = block->base;
	private = basedev->private;
	if (rq_data_dir(req) == READ)
		cmd = DASD_ECKD_CCW_READ_MT;
	else if (rq_data_dir(req) == WRITE)
		cmd = DASD_ECKD_CCW_WRITE_MT;
	else
		return ERR_PTR(-EINVAL);

	/* Check struct bio and count the number of blocks for the request. */
	count = 0;
	cidaw = 0;
	rq_for_each_segment(bv, req, iter) {
		if (bv.bv_len & (blksize - 1))
			/* Eckd can only do full blocks. */
			return ERR_PTR(-EINVAL);
		count += bv.bv_len >> (block->s2b_shift + 9);
		if (idal_is_needed (page_address(bv.bv_page), bv.bv_len))
			cidaw += bv.bv_len >> (block->s2b_shift + 9);
	}
	/* Paranoia. */
	if (count != last_rec - first_rec + 1)
		return ERR_PTR(-EINVAL);

	/* use the prefix command if available */
	use_prefix = private->features.feature[8] & 0x01;
	if (use_prefix) {
		/* 1x prefix + number of blocks */
		cplength = 2 + count;
		/* 1x prefix + cidaws*sizeof(long) */
		datasize = sizeof(struct PFX_eckd_data) +
			sizeof(struct LO_eckd_data) +
			cidaw * sizeof(unsigned long);
	} else {
		/* 1x define extent + 1x locate record + number of blocks */
		cplength = 2 + count;
		/* 1x define extent + 1x locate record + cidaws*sizeof(long) */
		datasize = sizeof(struct DE_eckd_data) +
			sizeof(struct LO_eckd_data) +
			cidaw * sizeof(unsigned long);
	}
	/* Find out the number of additional locate record ccws for cdl. */
	if (private->uses_cdl && first_rec < 2*blk_per_trk) {
		if (last_rec >= 2*blk_per_trk)
			count = 2*blk_per_trk - first_rec;
		cplength += count;
		datasize += count*sizeof(struct LO_eckd_data);
	}
	/* Allocate the ccw request. */
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
				   startdev, blk_mq_rq_to_pdu(req));
	if (IS_ERR(cqr))
		return cqr;
	ccw = cqr->cpaddr;
	/* First ccw is define extent or prefix. */
	if (use_prefix) {
		if (prefix(ccw++, cqr->data, first_trk,
			   last_trk, cmd, basedev, startdev) == -EAGAIN) {
			/* Clock not in sync and XRC is enabled.
			 * Try again later.
			 */
			dasd_sfree_request(cqr, startdev);
			return ERR_PTR(-EAGAIN);
		}
		idaws = (dma64_t *)(cqr->data + sizeof(struct PFX_eckd_data));
	} else {
		if (define_extent(ccw++, cqr->data, first_trk,
				  last_trk, cmd, basedev, 0) == -EAGAIN) {
			/* Clock not in sync and XRC is enabled.
			 * Try again later.
			 */
			dasd_sfree_request(cqr, startdev);
			return ERR_PTR(-EAGAIN);
		}
		idaws = (dma64_t *)(cqr->data + sizeof(struct DE_eckd_data));
	}
	/* Build locate_record+read/write/ccws. */
	LO_data = (struct LO_eckd_data *) (idaws + cidaw);
	recid = first_rec;
	if (private->uses_cdl == 0 || recid > 2*blk_per_trk) {
		/* Only standard blocks so there is just one locate record. */
		ccw[-1].flags |= CCW_FLAG_CC;
		locate_record(ccw++, LO_data++, first_trk, first_offs + 1,
			      last_rec - recid + 1, cmd, basedev, blksize);
	}
	rq_for_each_segment(bv, req, iter) {
		dst = bvec_virt(&bv);
		if (dasd_page_cache) {
			char *copy = kmem_cache_alloc(dasd_page_cache,
						      GFP_DMA | __GFP_NOWARN);
			if (copy && rq_data_dir(req) == WRITE)
				memcpy(copy + bv.bv_offset, dst, bv.bv_len);
			if (copy)
				dst = copy + bv.bv_offset;
		}
		for (off = 0; off < bv.bv_len; off += blksize) {
			sector_t trkid = recid;
			unsigned int recoffs = sector_div(trkid, blk_per_trk);
			rcmd = cmd;
			count = blksize;
			/* Locate record for cdl special block ? */
			if (private->uses_cdl && recid < 2*blk_per_trk) {
				if (dasd_eckd_cdl_special(blk_per_trk, recid)){
					rcmd |= 0x8;
					count = dasd_eckd_cdl_reclen(recid);
					if (count < blksize &&
					    rq_data_dir(req) == READ)
						memset(dst + count, 0xe5,
						       blksize - count);
				}
				ccw[-1].flags |= CCW_FLAG_CC;
				locate_record(ccw++, LO_data++,
					      trkid, recoffs + 1,
					      1, rcmd, basedev, count);
			}
			/* Locate record for standard blocks ? */
			if (private->uses_cdl && recid == 2*blk_per_trk) {
				ccw[-1].flags |= CCW_FLAG_CC;
				locate_record(ccw++, LO_data++,
					      trkid, recoffs + 1,
					      last_rec - recid + 1,
					      cmd, basedev, count);
			}
			/* Read/write ccw. */
			ccw[-1].flags |= CCW_FLAG_CC;
			ccw->cmd_code = rcmd;
			ccw->count = count;
			if (idal_is_needed(dst, blksize)) {
				ccw->cda = virt_to_dma32(idaws);
				ccw->flags = CCW_FLAG_IDA;
				idaws = idal_create_words(idaws, dst, blksize);
			} else {
				ccw->cda = virt_to_dma32(dst);
				ccw->flags = 0;
			}
			ccw++;
			dst += blksize;
			recid++;
		}
	}
	if (blk_noretry_request(req) ||
	    block->base->features & DASD_FEATURE_FAILFAST)
		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->startdev = startdev;
	cqr->memdev = startdev;
	cqr->block = block;
	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
	cqr->lpm = dasd_path_get_ppm(startdev);
	cqr->retries = startdev->default_retries;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	/* Set flags to suppress output for expected errors */
	if (dasd_eckd_is_ese(basedev)) {
		set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
	}

	return cqr;
}

static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_track(
					       struct dasd_device *startdev,
					       struct dasd_block *block,
					       struct request *req,
					       sector_t first_rec,
					       sector_t last_rec,
					       sector_t first_trk,
					       sector_t last_trk,
					       unsigned int first_offs,
					       unsigned int last_offs,
					       unsigned int blk_per_trk,
					       unsigned int blksize)
{
	dma64_t *idaws;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	struct req_iterator iter;
	struct bio_vec bv;
	char *dst, *idaw_dst;
	unsigned int cidaw, cplength, datasize;
	unsigned int tlf;
	sector_t recid;
	unsigned char cmd;
	struct dasd_device *basedev;
	unsigned int trkcount, count, count_to_trk_end;
	unsigned int idaw_len, seg_len, part_len, len_to_track_end;
	unsigned char new_track, end_idaw;
	sector_t trkid;
	unsigned int recoffs;

	basedev = block->base;
	if (rq_data_dir(req) == READ)
		cmd = DASD_ECKD_CCW_READ_TRACK_DATA;
	else if (rq_data_dir(req) == WRITE)
		cmd = DASD_ECKD_CCW_WRITE_TRACK_DATA;
	else
		return ERR_PTR(-EINVAL);

	/* Track based I/O needs IDAWs for each page, and not just for
	 * 64 bit addresses. We need additional idals for pages
	 * that get filled from two tracks, so we use the number
	 * of records as upper limit.
	 */
	cidaw = last_rec - first_rec + 1;
	trkcount = last_trk - first_trk + 1;

	/* 1x prefix + one read/write ccw per track */
	cplength = 1 + trkcount;

	datasize = sizeof(struct PFX_eckd_data) + cidaw * sizeof(unsigned long);

	/* Allocate the ccw request. */
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength, datasize,
				   startdev, blk_mq_rq_to_pdu(req));
	if (IS_ERR(cqr))
		return cqr;
	ccw = cqr->cpaddr;
	/* transfer length factor: how many bytes to read from the last track */
	if (first_trk == last_trk)
		tlf = last_offs - first_offs + 1;
	else
		tlf = last_offs + 1;
	tlf *= blksize;

	if (prefix_LRE(ccw++, cqr->data, first_trk,
		       last_trk, cmd, basedev, startdev,
		       1 /* format */, first_offs + 1,
		       trkcount, blksize,
		       tlf) == -EAGAIN) {
		/* Clock not in sync and XRC is enabled.
		 * Try again later.
		 */
		dasd_sfree_request(cqr, startdev);
		return ERR_PTR(-EAGAIN);
	}

	/*
	 * The translation of request into ccw programs must meet the
	 * following conditions:
	 * - all idaws but the first and the last must address full pages
	 *   (or 2K blocks on 31-bit)
	 * - the scope of a ccw and it's idal ends with the track boundaries
	 */
	idaws = (dma64_t *)(cqr->data + sizeof(struct PFX_eckd_data));
	recid = first_rec;
	new_track = 1;
	end_idaw = 0;
	len_to_track_end = 0;
	idaw_dst = NULL;
	idaw_len = 0;
	rq_for_each_segment(bv, req, iter) {
		dst = bvec_virt(&bv);
		seg_len = bv.bv_len;
		while (seg_len) {
			if (new_track) {
				trkid = recid;
				recoffs = sector_div(trkid, blk_per_trk);
				count_to_trk_end = blk_per_trk - recoffs;
				count = min((last_rec - recid + 1),
					    (sector_t)count_to_trk_end);
				len_to_track_end = count * blksize;
				ccw[-1].flags |= CCW_FLAG_CC;
				ccw->cmd_code = cmd;
				ccw->count = len_to_track_end;
				ccw->cda = virt_to_dma32(idaws);
				ccw->flags = CCW_FLAG_IDA;
				ccw++;
				recid += count;
				new_track = 0;
				/* first idaw for a ccw may start anywhere */
				if (!idaw_dst)
					idaw_dst = dst;
			}
			/* If we start a new idaw, we must make sure that it
			 * starts on an IDA_BLOCK_SIZE boundary.
			 * If we continue an idaw, we must make sure that the
			 * current segment begins where the so far accumulated
			 * idaw ends
			 */
			if (!idaw_dst) {
				if ((unsigned long)(dst) & (IDA_BLOCK_SIZE - 1)) {
					dasd_sfree_request(cqr, startdev);
					return ERR_PTR(-ERANGE);
				} else
					idaw_dst = dst;
			}
			if ((idaw_dst + idaw_len) != dst) {
				dasd_sfree_request(cqr, startdev);
				return ERR_PTR(-ERANGE);
			}
			part_len = min(seg_len, len_to_track_end);
			seg_len -= part_len;
			dst += part_len;
			idaw_len += part_len;
			len_to_track_end -= part_len;
			/* collected memory area ends on an IDA_BLOCK border,
			 * -> create an idaw
			 * idal_create_words will handle cases where idaw_len
			 * is larger then IDA_BLOCK_SIZE
			 */
			if (!((unsigned long)(idaw_dst + idaw_len) & (IDA_BLOCK_SIZE - 1)))
				end_idaw = 1;
			/* We also need to end the idaw at track end */
			if (!len_to_track_end) {
				new_track = 1;
				end_idaw = 1;
			}
			if (end_idaw) {
				idaws = idal_create_words(idaws, idaw_dst,
							  idaw_len);
				idaw_dst = NULL;
				idaw_len = 0;
				end_idaw = 0;
			}
		}
	}

	if (blk_noretry_request(req) ||
	    block->base->features & DASD_FEATURE_FAILFAST)
		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->startdev = startdev;
	cqr->memdev = startdev;
	cqr->block = block;
	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
	cqr->lpm = dasd_path_get_ppm(startdev);
	cqr->retries = startdev->default_retries;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	/* Set flags to suppress output for expected errors */
	if (dasd_eckd_is_ese(basedev))
		set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);

	return cqr;
}

static int prepare_itcw(struct itcw *itcw,
			unsigned int trk, unsigned int totrk, int cmd,
			struct dasd_device *basedev,
			struct dasd_device *startdev,
			unsigned int rec_on_trk, int count,
			unsigned int blksize,
			unsigned int total_data_size,
			unsigned int tlf,
			unsigned int blk_per_trk)
{
	u8 pfxbuf[sizeof(struct PFX_eckd_data) + 2] __aligned(8);
	struct PFX_eckd_data *pfxdata = (struct PFX_eckd_data *)pfxbuf;
	struct dasd_eckd_private *basepriv, *startpriv;
	struct DE_eckd_data *dedata;
	struct LRE_eckd_data *lredata;
	struct dcw *dcw;
	int pfxsize;

	u32 begcyl, endcyl;
	u16 heads, beghead, endhead;
	u8 pfx_cmd;

	int rc = 0;
	int sector = 0;
	int dn, d;

	pfxsize = sizeof(struct PFX_eckd_data);
	/* prefix + LRE extended data */
	if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK)
		pfxsize += 2;

	memset(pfxbuf, 0, pfxsize);

	/* setup prefix data */
	basepriv = basedev->private;
	startpriv = startdev->private;
	dedata = &pfxdata->define_extent;
	lredata = &pfxdata->locate_record;

	pfxdata->format = 1; /* PFX with LRE */
	/* cached copies - conf.ned may be freed under us by the reload worker */
	pfxdata->base_address = READ_ONCE(basepriv->ned_ua);
	pfxdata->base_lss = READ_ONCE(basepriv->ned_lss);
	pfxdata->validity.define_extent = 1;

	/* private uid is kept up to date, conf_data may be outdated */
	if (startpriv->uid.type == UA_BASE_PAV_ALIAS)
		pfxdata->validity.verify_base = 1;

	if (startpriv->uid.type == UA_HYPER_PAV_ALIAS) {
		pfxdata->validity.verify_base = 1;
		pfxdata->validity.hyper_pav = 1;
	}

	switch (cmd) {
	case DASD_ECKD_CCW_READ_TRACK_DATA:
		dedata->mask.perm = 0x1;
		dedata->attributes.operation = basepriv->attrib.operation;
		dedata->blk_size = blksize;
		dedata->ga_extended |= 0x42;
		lredata->operation.orientation = 0x0;
		lredata->operation.operation = 0x0C;
		lredata->auxiliary.check_bytes = 0x01;
		pfx_cmd = DASD_ECKD_CCW_PFX_READ;
		break;
	case DASD_ECKD_CCW_WRITE_TRACK_DATA:
		dedata->mask.perm = 0x02;
		dedata->attributes.operation = basepriv->attrib.operation;
		dedata->blk_size = blksize;
		rc = set_timestamp(NULL, dedata, basedev);
		dedata->ga_extended |= 0x42;
		lredata->operation.orientation = 0x0;
		lredata->operation.operation = 0x3F;
		lredata->extended_operation = 0x23;
		lredata->auxiliary.check_bytes = 0x2;
		/*
		 * If XRC is supported the System Time Stamp is set. The
		 * validity of the time stamp must be reflected in the prefix
		 * data as well.
		 */
		if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
			pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid' */
		pfx_cmd = DASD_ECKD_CCW_PFX;
		break;
	case DASD_ECKD_CCW_WRITE_FULL_TRACK:
		dedata->mask.perm = 0x3;
		dedata->mask.auth = 0x00;
		dedata->attributes.operation = basepriv->attrib.operation;
		dedata->blk_size = blksize;
		dedata->ga_extended |= 0x42;
		rc = set_timestamp(NULL, dedata, basedev);
		lredata->operation.orientation = 0x0;
		lredata->operation.operation = 0x3F;
		lredata->extended_operation = 0x11;
		lredata->auxiliary.check_bytes = 0x2;
		lredata->extended_parameter_length = 0x02;
		if (count > 8) {
			lredata->extended_parameter[0] = 0xFF;
			lredata->extended_parameter[1] = 0xFF;
			lredata->extended_parameter[1] <<= (16 - count);
		} else {
			lredata->extended_parameter[0] = 0xFF;
			lredata->extended_parameter[0] <<= (8 - count);
			lredata->extended_parameter[1] = 0x00;
		}
		sector = 0xFF;
		/*
		 * If XRC is supported the System Time Stamp is set. The
		 * validity of the time stamp must be reflected in the prefix
		 * data as well.
		 */
		if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
			pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid' */
		pfx_cmd = DASD_ECKD_CCW_PFX;
		break;
	case DASD_ECKD_CCW_READ_COUNT_MT:
		dedata->mask.perm = 0x1;
		dedata->attributes.operation = DASD_BYPASS_CACHE;
		dedata->ga_extended |= 0x42;
		dedata->blk_size = blksize;
		lredata->operation.orientation = 0x2;
		lredata->operation.operation = 0x16;
		lredata->auxiliary.check_bytes = 0x01;
		pfx_cmd = DASD_ECKD_CCW_PFX_READ;
		break;
	default:
		DBF_DEV_EVENT(DBF_ERR, basedev,
			      "prepare itcw, unknown opcode 0x%x", cmd);
		BUG();
		break;
	}
	if (rc)
		return rc;

	dedata->attributes.mode = 0x3;	/* ECKD */

	heads = basepriv->rdc_data.trk_per_cyl;
	begcyl = trk / heads;
	beghead = trk % heads;
	endcyl = totrk / heads;
	endhead = totrk % heads;

	/* check for sequential prestage - enhance cylinder range */
	if (dedata->attributes.operation == DASD_SEQ_PRESTAGE ||
	    dedata->attributes.operation == DASD_SEQ_ACCESS) {

		if (endcyl + basepriv->attrib.nr_cyl < basepriv->real_cyl)
			endcyl += basepriv->attrib.nr_cyl;
		else
			endcyl = (basepriv->real_cyl - 1);
	}

	set_ch_t(&dedata->beg_ext, begcyl, beghead);
	set_ch_t(&dedata->end_ext, endcyl, endhead);

	dedata->ep_format = 0x20; /* records per track is valid */
	dedata->ep_rec_per_track = blk_per_trk;

	if (rec_on_trk) {
		switch (basepriv->rdc_data.dev_type) {
		case 0x3390:
			dn = ceil_quot(blksize + 6, 232);
			d = 9 + ceil_quot(blksize + 6 * (dn + 1), 34);
			sector = (49 + (rec_on_trk - 1) * (10 + d)) / 8;
			break;
		case 0x3380:
			d = 7 + ceil_quot(blksize + 12, 32);
			sector = (39 + (rec_on_trk - 1) * (8 + d)) / 7;
			break;
		}
	}

	if (cmd == DASD_ECKD_CCW_READ_COUNT_MT) {
		lredata->auxiliary.length_valid = 0;
		lredata->auxiliary.length_scope = 0;
		lredata->sector = 0xff;
	} else {
		lredata->auxiliary.length_valid = 1;
		lredata->auxiliary.length_scope = 1;
		lredata->sector = sector;
	}
	lredata->auxiliary.imbedded_ccw_valid = 1;
	lredata->length = tlf;
	lredata->imbedded_ccw = cmd;
	lredata->count = count;
	set_ch_t(&lredata->seek_addr, begcyl, beghead);
	lredata->search_arg.cyl = lredata->seek_addr.cyl;
	lredata->search_arg.head = lredata->seek_addr.head;
	lredata->search_arg.record = rec_on_trk;

	dcw = itcw_add_dcw(itcw, pfx_cmd, 0,
			   pfxdata, pfxsize, total_data_size);
	return PTR_ERR_OR_ZERO(dcw);
}

static struct dasd_ccw_req *dasd_eckd_build_cp_tpm_track(
					       struct dasd_device *startdev,
					       struct dasd_block *block,
					       struct request *req,
					       sector_t first_rec,
					       sector_t last_rec,
					       sector_t first_trk,
					       sector_t last_trk,
					       unsigned int first_offs,
					       unsigned int last_offs,
					       unsigned int blk_per_trk,
					       unsigned int blksize)
{
	struct dasd_ccw_req *cqr;
	struct req_iterator iter;
	struct bio_vec bv;
	char *dst;
	unsigned int trkcount, ctidaw;
	unsigned char cmd;
	struct dasd_device *basedev;
	unsigned int tlf;
	struct itcw *itcw;
	struct tidaw *last_tidaw = NULL;
	int itcw_op;
	size_t itcw_size;
	u8 tidaw_flags;
	unsigned int seg_len, part_len, len_to_track_end;
	unsigned char new_track;
	sector_t recid, trkid;
	unsigned int offs;
	unsigned int count, count_to_trk_end;
	int ret;

	basedev = block->base;
	if (rq_data_dir(req) == READ) {
		cmd = DASD_ECKD_CCW_READ_TRACK_DATA;
		itcw_op = ITCW_OP_READ;
	} else if (rq_data_dir(req) == WRITE) {
		cmd = DASD_ECKD_CCW_WRITE_TRACK_DATA;
		itcw_op = ITCW_OP_WRITE;
	} else
		return ERR_PTR(-EINVAL);

	/* trackbased I/O needs address all memory via TIDAWs,
	 * not just for 64 bit addresses. This allows us to map
	 * each segment directly to one tidaw.
	 * In the case of write requests, additional tidaws may
	 * be needed when a segment crosses a track boundary.
	 */
	trkcount = last_trk - first_trk + 1;
	ctidaw = 0;
	rq_for_each_segment(bv, req, iter) {
		++ctidaw;
	}
	if (rq_data_dir(req) == WRITE)
		ctidaw += (last_trk - first_trk);

	/* Allocate the ccw request. */
	itcw_size = itcw_calc_size(0, ctidaw, 0);
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev,
				   blk_mq_rq_to_pdu(req));
	if (IS_ERR(cqr))
		return cqr;

	/* transfer length factor: how many bytes to read from the last track */
	if (first_trk == last_trk)
		tlf = last_offs - first_offs + 1;
	else
		tlf = last_offs + 1;
	tlf *= blksize;

	itcw = itcw_init(cqr->data, itcw_size, itcw_op, 0, ctidaw, 0);
	if (IS_ERR(itcw)) {
		ret = -EINVAL;
		goto out_error;
	}
	cqr->cpaddr = itcw_get_tcw(itcw);
	if (prepare_itcw(itcw, first_trk, last_trk,
			 cmd, basedev, startdev,
			 first_offs + 1,
			 trkcount, blksize,
			 (last_rec - first_rec + 1) * blksize,
			 tlf, blk_per_trk) == -EAGAIN) {
		/* Clock not in sync and XRC is enabled.
		 * Try again later.
		 */
		ret = -EAGAIN;
		goto out_error;
	}
	len_to_track_end = 0;
	/*
	 * A tidaw can address 4k of memory, but must not cross page boundaries
	 * We can let the block layer handle this by setting seg_boundary_mask
	 * to page boundaries and max_segment_size to page size when setting up
	 * the request queue.
	 * For write requests, a TIDAW must not cross track boundaries, because
	 * we have to set the CBC flag on the last tidaw for each track.
	 */
	if (rq_data_dir(req) == WRITE) {
		new_track = 1;
		recid = first_rec;
		rq_for_each_segment(bv, req, iter) {
			dst = bvec_virt(&bv);
			seg_len = bv.bv_len;
			while (seg_len) {
				if (new_track) {
					trkid = recid;
					offs = sector_div(trkid, blk_per_trk);
					count_to_trk_end = blk_per_trk - offs;
					count = min((last_rec - recid + 1),
						    (sector_t)count_to_trk_end);
					len_to_track_end = count * blksize;
					recid += count;
					new_track = 0;
				}
				part_len = min(seg_len, len_to_track_end);
				seg_len -= part_len;
				len_to_track_end -= part_len;
				/* We need to end the tidaw at track end */
				if (!len_to_track_end) {
					new_track = 1;
					tidaw_flags = TIDAW_FLAGS_INSERT_CBC;
				} else
					tidaw_flags = 0;
				last_tidaw = itcw_add_tidaw(itcw, tidaw_flags,
							    dst, part_len);
				if (IS_ERR(last_tidaw)) {
					ret = -EINVAL;
					goto out_error;
				}
				dst += part_len;
			}
		}
	} else {
		rq_for_each_segment(bv, req, iter) {
			dst = bvec_virt(&bv);
			last_tidaw = itcw_add_tidaw(itcw, 0x00,
						    dst, bv.bv_len);
			if (IS_ERR(last_tidaw)) {
				ret = -EINVAL;
				goto out_error;
			}
		}
	}
	last_tidaw->flags |= TIDAW_FLAGS_LAST;
	last_tidaw->flags &= ~TIDAW_FLAGS_INSERT_CBC;
	itcw_finalize(itcw);

	if (blk_noretry_request(req) ||
	    block->base->features & DASD_FEATURE_FAILFAST)
		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->cpmode = 1;
	cqr->startdev = startdev;
	cqr->memdev = startdev;
	cqr->block = block;
	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
	cqr->lpm = dasd_path_get_ppm(startdev);
	cqr->retries = startdev->default_retries;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	/* Set flags to suppress output for expected errors */
	if (dasd_eckd_is_ese(basedev)) {
		set_bit(DASD_CQR_SUPPRESS_NRF, &cqr->flags);
		set_bit(DASD_CQR_SUPPRESS_IT, &cqr->flags);
	}

	return cqr;
out_error:
	dasd_sfree_request(cqr, startdev);
	return ERR_PTR(ret);
}

static __always_inline bool crosses_page(const void *addr, size_t len)
{
	return len && (offset_in_page(addr) + len > PAGE_SIZE);
}

static __always_inline void *reserve_nocross(char **p, size_t *space, size_t len)
{
	size_t pad = crosses_page(*p, len) ? PAGE_SIZE - offset_in_page(*p) : 0;
	void *ret;

	if (*space < pad + len)
		return NULL;	/* out of space */

	*p += pad;
	*space -= pad;
	ret = *p;
	*p += len;
	*space -= len;
	return ret;
}

/*
 * Helpers for dasd_eckd_build_cp_tpm_writefulltrack(): append the TIDAWs for
 * one track-image element (R0 header, a count + data record, or the trailing
 * pseudo track end count) to the itcw. Return the last TIDAW, or NULL on failure.
 */
static struct tidaw *add_track_r0(struct itcw *itcw, char **fill,
				  size_t *fillsize, u32 cyl, u16 head)
{
	struct tidaw *tidaw;
	struct eckd_r0 *r0;

	r0 = reserve_nocross(fill, fillsize, sizeof(*r0));
	if (WARN_ON_ONCE(!r0))
		return NULL;
	set_chr_t(r0, cyl, head, 0);
	r0->count.dl = 8;
	tidaw = itcw_add_tidaw(itcw, 0, r0, sizeof(*r0));
	return IS_ERR_OR_NULL(tidaw) ? NULL : tidaw;
}

static struct tidaw *add_track_record(struct itcw *itcw, char **fill,
				      size_t *fillsize, u32 cyl, u16 head,
				      u8 rec, void *data, u32 dl)
{
	struct eckd_count *count;
	struct tidaw *tidaw;

	count = reserve_nocross(fill, fillsize, sizeof(*count));
	if (WARN_ON_ONCE(!count))
		return NULL;
	set_chr_t(count, cyl, head, rec);
	count->dl = dl;
	tidaw = itcw_add_tidaw(itcw, 0, count, sizeof(*count));
	if (IS_ERR_OR_NULL(tidaw))
		return NULL;
	tidaw = itcw_add_tidaw(itcw, 0, data, dl);
	return IS_ERR_OR_NULL(tidaw) ? NULL : tidaw;
}

static struct tidaw *add_track_end(struct itcw *itcw, char **fill,
				   size_t *fillsize)
{
	struct eckd_count *count;
	struct tidaw *tidaw;

	count = reserve_nocross(fill, fillsize, sizeof(*count));
	if (WARN_ON_ONCE(!count))
		return NULL;
	count->cyl = 0xffff;
	count->head = 0xffff;
	count->dl = 0xffff;
	count->record = 0xff;
	count->kl = 0xff;
	tidaw = itcw_add_tidaw(itcw, TIDAW_FLAGS_INSERT_CBC, count, sizeof(*count));
	return IS_ERR_OR_NULL(tidaw) ? NULL : tidaw;
}

static struct dasd_ccw_req *
dasd_eckd_build_cp_tpm_writefulltrack(struct dasd_device *startdev,
				      struct dasd_block *block,
				      struct request *req,
				      sector_t first_rec,
				      sector_t last_rec,
				      sector_t first_trk,
				      sector_t last_trk,
				      unsigned int first_offs,
				      unsigned int last_offs,
				      unsigned int blk_per_trk,
				      unsigned int blksize,
				      struct dasd_ccw_req *ocqr)
{
	struct dasd_eckd_private *private = block->base->private;
	unsigned int seg_len, part_len, len_to_track_end;
	unsigned int count, count_to_trk_end, offs;
	unsigned int trkcount, ctidaw, tlf;
	int itcw_op, rec_count, datasize;
	struct tidaw *last_tidaw = NULL;
	sector_t recid, trkid, curr_trk;
	unsigned char cmd, new_track;
	struct dasd_device *basedev;
	size_t itcw_size, fillsize;
	struct dasd_ccw_req *cqr;
	struct req_iterator iter;
	char *dst, *filldata;
	unsigned long flags;
	struct itcw *itcw;
	struct bio_vec bv;
	int ret = -EINVAL;
	void *nullrecord;
	u16 heads, head;
	u32 cyl;
	u8 rec;

	basedev = block->base;
	cmd = DASD_ECKD_CCW_WRITE_FULL_TRACK;
	itcw_op = ITCW_OP_WRITE;

	/*
	 * trackbased I/O needs address all memory via TIDAWs,
	 * not just for 64 bit addresses. This allows us to map
	 * each segment directly to one tidaw.
	 * In the case of write requests, additional tidaws may
	 * be needed when a segment crosses a track boundary.
	 * Per track we emit one R0 tidaw, two tidaws per record (count field
	 * plus data - a record never crosses a track or page boundary, as
	 * part_len is clamped to both blksize and the track end), and one track
	 * end tidaw: 2 * blk_per_trk + 2.
	 * Round the +2 up to blk_per_trk-independent headroom via 2 * (blk_per_trk + 2).
	 */
	trkcount = last_trk - first_trk + 1;
	ctidaw = trkcount * 2 * (blk_per_trk + 2);

	/*
	 * build_cp (ocqr == NULL): the request owns its CCW program - block in
	 * the pdu, ITCW in ccw_chunks. ese_format (ocqr != NULL): the failing
	 * origin still owns its pdu, so take the replacement from ese_chunks.
	 */
	itcw_size = itcw_calc_size(0, ctidaw, 0);
	if (ocqr)
		cqr = dasd_fmalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev);
	else
		cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 0, itcw_size, startdev,
					   blk_mq_rq_to_pdu(req));
	if (IS_ERR(cqr))
		return cqr;
	fillsize = trkcount * (sizeof(struct eckd_r0) +
			       (sizeof(struct eckd_count) * (blk_per_trk + 2)));
	/*
	 * reserve_nocross() pads elements away from page boundaries and draws
	 * that padding from fillsize; budget one element per page the buffer
	 * may span so it never runs short.
	 */
	fillsize += (fillsize / PAGE_SIZE + 1) * sizeof(struct eckd_r0);
	spin_lock_irqsave(&startdev->mem_lock, flags);
	filldata  = dasd_alloc_chunk(&startdev->fill_chunks, fillsize);
	spin_unlock_irqrestore(&startdev->mem_lock, flags);
	if (!filldata) {
		ret = -ENOMEM;
		goto out_error;
	}
	memset(filldata, 0, fillsize);
	cqr->filldata = filldata;

	nullrecord = startdev->nulldata;

	/* count + data for each record, plus r0 and the pseudo count */
	tlf = blk_per_trk * (blksize + sizeof(struct eckd_count));
	tlf += sizeof(struct eckd_r0) + sizeof(struct eckd_count);

	itcw = itcw_init(cqr->data, itcw_size, itcw_op, 0, ctidaw, 0);
	if (IS_ERR(itcw)) {
		ret = -EINVAL;
		goto out_error;
	}
	cqr->cpaddr = itcw_get_tcw(itcw);
	datasize = trkcount * tlf;
	if (prepare_itcw(itcw, first_trk, last_trk,
			 cmd, basedev, startdev,
			 0,
			 trkcount, blksize,
			 datasize,
			 tlf,
			 blk_per_trk) == -EAGAIN) {
		/* Clock not in sync and XRC is enabled.
		 * Try again later.
		 */
		ret = -EAGAIN;
		goto out_error;
	}
	heads = private->rdc_data.trk_per_cyl;
	/*
	 * A tidaw can address 4k of memory, but must not cross page boundaries
	 * We can let the block layer handle this by setting seg_boundary_mask
	 * to page boundaries and max_segment_size to page size when setting up
	 * the request queue.
	 */
	curr_trk = first_trk;
	recid = first_rec;
	trkid = recid;
	offs = sector_div(trkid, blk_per_trk);
	count = blk_per_trk;
	len_to_track_end = count * blksize;
	recid += count - first_offs;
	new_track = 0;

	/* the R0 header of the first track */
	cyl = curr_trk / heads;
	head = curr_trk % heads;
	last_tidaw = add_track_r0(itcw, &filldata, &fillsize, cyl, head);
	if (!last_tidaw)
		goto out_error;

	/* empty records before the first data record */
	for (int i = 1; i <= first_offs; i++) {
		len_to_track_end -= blksize;
		last_tidaw = add_track_record(itcw, &filldata, &fillsize,
					      cyl, head, i, nullrecord, blksize);
		if (!last_tidaw)
			goto out_error;
	}

	/* process data records */
	rec = first_offs + 1;
	rec_count = 0;
	rq_for_each_segment(bv, req, iter) {
		dst = bvec_virt(&bv);
		seg_len = bv.bv_len;
		while (seg_len) {
			if (new_track) {
				trkid = recid;
				offs = sector_div(trkid, blk_per_trk);
				count_to_trk_end = blk_per_trk - offs;
				count = min((last_rec - recid + 1),
					    (sector_t)count_to_trk_end);
				/*
				 * Size to the physical track end: a short last
				 * track is padded in out_skip, so the track-end
				 * marker must not be emitted early here.
				 */
				len_to_track_end = count_to_trk_end * blksize;
				recid += count;
				new_track = 0;
				/* the R0 header of the next track */
				cyl = curr_trk / heads;
				head = curr_trk % heads;
				last_tidaw = add_track_r0(itcw, &filldata,
							  &fillsize, cyl, head);
				if (!last_tidaw)
					goto out_error;
				rec = 1;
			}
			/*
			 * One count + data record per block: a bvec segment can
			 * be up to a page, so clamp to blksize - otherwise the
			 * count field would describe one oversized record instead
			 * of several blksize ones for sub-page block sizes.
			 */
			part_len = min(seg_len, len_to_track_end);
			part_len = min(part_len, blksize);
			seg_len -= part_len;
			len_to_track_end -= part_len;
			/*
			 * This block ends the track; the next one starts a new
			 * track. The track-end marker emitted below carries the
			 * CBC flag.
			 */
			if (!len_to_track_end)
				new_track = 1;

			last_tidaw = add_track_record(itcw, &filldata, &fillsize,
						      cyl, head, rec, dst, part_len);
			if (!last_tidaw)
				goto out_error;

			if (new_track) {
				/* add track end marker */
				last_tidaw = add_track_end(itcw, &filldata,
							   &fillsize);
				if (!last_tidaw)
					goto out_error;
				curr_trk++;
			}
			rec++;
			dst += part_len;
			rec_count++;
			if (rec_count >= (last_rec - first_rec + 1))
				goto out_skip;
		}
	}

out_skip:
	new_track = 0;
	/* empty records after the last data record */
	for (int i = last_offs + 2; i <= blk_per_trk; i++) {
		len_to_track_end -= blksize;
		last_tidaw = add_track_record(itcw, &filldata, &fillsize,
					      cyl, head, i, nullrecord, blksize);
		if (!last_tidaw)
			goto out_error;
		new_track = 1;
	}

	/* add track end marker */
	if (new_track) {
		last_tidaw = add_track_end(itcw, &filldata, &fillsize);
		if (!last_tidaw)
			goto out_error;
	}

	last_tidaw->flags |= TIDAW_FLAGS_LAST;
	last_tidaw->flags &= ~TIDAW_FLAGS_INSERT_CBC;
	itcw_finalize(itcw);

	if (blk_noretry_request(req) ||
	    block->base->features & DASD_FEATURE_FAILFAST)
		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->cpmode = 1;
	cqr->startdev = startdev;
	cqr->memdev = startdev;
	cqr->block = block;
	cqr->expires = startdev->default_expires * HZ;	/* default 5 minutes */
	cqr->lpm = dasd_path_get_ppm(startdev);
	cqr->retries = startdev->default_retries;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	return cqr;
out_error:
	/* dasd_sfree_request frees from the right pool via cqr->mem_chunk */
	dasd_sfree_request(cqr, startdev);
	return ERR_PTR(ret);
}

static struct dasd_ccw_req *
dasd_eckd_build_cp_discard(struct dasd_device *device, struct dasd_block *block,
			   struct request *req, sector_t first_trk,
			   sector_t last_trk, unsigned int first_offs,
			   unsigned int last_offs, unsigned int blk_per_trk)
{
	struct dasd_eckd_private *private = device->private;
	sector_t first_ext_trk, last_ext_end, last_ext_trk;
	unsigned int trks_per_ext;

	trks_per_ext = dasd_eckd_ext_size(device) * private->rdc_data.trk_per_cyl;
	if (!trks_per_ext)
		return ERR_PTR(-EOPNOTSUPP);

	/*
	 * A discard range is rarely track-aligned: fstrim is FS-block granular
	 * and discard_granularity is only a hint. If it starts or ends mid-track,
	 * that boundary track still holds live records outside the range, so drop
	 * it from the whole-track span first. Otherwise a partial boundary track
	 * that happens to sit on an extent boundary would be released together
	 * with its live records resulting in silent data loss
	 */
	if (first_offs)				/* partial first track */
		first_trk++;
	if (last_offs != blk_per_trk - 1) {	/* partial last track */
		if (!last_trk)
			return ERR_PTR(-EOPNOTSUPP);
		last_trk--;
	}
	if (first_trk > last_trk)
		return ERR_PTR(-EOPNOTSUPP);	/* no whole track fully covered */

	/*
	 * RAS releases whole extents. Only release extents that lie entirely
	 * within the (now whole-track) discard range by rounding inward to extent
	 * boundaries - an extent shared with a live allocation must never be
	 * released. If no whole extent is covered there is nothing to release
	 * safely (e.g. a sub-extent discard, unavoidable with large extents), so
	 * reject the request rather than release too much.
	 */
	first_ext_trk = roundup(first_trk, trks_per_ext);
	/* one past the last whole extent inside the range (exclusive) */
	last_ext_end = rounddown(last_trk + 1, trks_per_ext);
	if (first_ext_trk >= last_ext_end)
		return ERR_PTR(-EOPNOTSUPP);
	/* inclusive last track; the guard above keeps this from underflowing */
	last_ext_trk = last_ext_end - 1;

	return dasd_eckd_dso_ras(device, block, req, first_ext_trk,
				 last_ext_trk, 1);
}

static struct dasd_ccw_req *dasd_eckd_build_cp(struct dasd_device *startdev,
					       struct dasd_block *block,
					       struct request *req)
{
	int cmdrtd, cmdwtd;
	int use_prefix;
	int fcx_multitrack;
	struct dasd_eckd_private *private;
	struct dasd_device *basedev;
	sector_t first_rec, last_rec;
	sector_t first_trk, last_trk;
	unsigned int first_offs, last_offs;
	unsigned int blk_per_trk, blksize;
	int cdlspecial;
	unsigned int data_size;
	struct dasd_ccw_req *cqr;

	basedev = block->base;
	if (dasd_ese_adaptive(basedev))
		dasd_ese_heuristic_tick(basedev);
	else
		/* re-assert the endpoint mode: a stale heuristic write cannot stick */
		basedev->fulltrack = (basedev->ft_bias >= DASD_FT_BIAS_MAX) ? 1 : 0;
	private = basedev->private;

	/* Calculate number of blocks/records per track. */
	blksize = block->bp_block;
	blk_per_trk = recs_per_track(&private->rdc_data, 0, blksize);
	if (blk_per_trk == 0)
		return ERR_PTR(-EINVAL);
	/* Calculate record id of first and last block. */
	first_rec = first_trk = blk_rq_pos(req) >> block->s2b_shift;
	first_offs = sector_div(first_trk, blk_per_trk);
	last_rec = last_trk =
		(blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
	last_offs = sector_div(last_trk, blk_per_trk);
	cdlspecial = (private->uses_cdl && first_rec < 2*blk_per_trk);

	if (req_op(req) == REQ_OP_DISCARD)
		return dasd_eckd_build_cp_discard(startdev, block, req,
						  first_trk, last_trk,
						  first_offs, last_offs,
						  blk_per_trk);

	fcx_multitrack = private->features.feature[40] & 0x20;
	data_size = blk_rq_bytes(req);
	if (data_size % blksize || data_size == 0)
		return ERR_PTR(-EINVAL);
	/* tpm write request add CBC data on each track boundary */
	if (rq_data_dir(req) == WRITE)
		data_size += (last_trk - first_trk) * 4;

	/* is read track data and write track data in command mode supported? */
	cmdrtd = private->features.feature[9] & 0x20;
	cmdwtd = private->features.feature[12] & 0x40;
	use_prefix = private->features.feature[8] & 0x01;

	cqr = NULL;
	if (cdlspecial || dasd_page_cache) {
		/* do nothing, just fall through to the cmd mode single case */
	} else if ((data_size <= private->fcx_max_data)
		   && (fcx_multitrack || (first_trk == last_trk))) {
		if (!first_offs && (last_offs + 1 == blk_per_trk) &&
		    rq_data_dir(req) == WRITE && basedev->fulltrack) {
			cqr = dasd_eckd_build_cp_tpm_writefulltrack(startdev, block, req,
								    first_rec, last_rec,
								    first_trk, last_trk,
								    first_offs, last_offs,
								    blk_per_trk, blksize, NULL);
		} else {
			cqr = dasd_eckd_build_cp_tpm_track(startdev, block, req,
							   first_rec, last_rec,
							   first_trk, last_trk,
							   first_offs, last_offs,
							   blk_per_trk, blksize);
		}
		if (IS_ERR(cqr) && (PTR_ERR(cqr) != -EAGAIN) &&
		    (PTR_ERR(cqr) != -ENOMEM))
			cqr = NULL;
	} else if (use_prefix &&
		   (((rq_data_dir(req) == READ) && cmdrtd) ||
		    ((rq_data_dir(req) == WRITE) && cmdwtd))) {
		cqr = dasd_eckd_build_cp_cmd_track(startdev, block, req,
						   first_rec, last_rec,
						   first_trk, last_trk,
						   first_offs, last_offs,
						   blk_per_trk, blksize);
		if (IS_ERR(cqr) && (PTR_ERR(cqr) != -EAGAIN) &&
		    (PTR_ERR(cqr) != -ENOMEM))
			cqr = NULL;
	}
	if (!cqr)
		cqr = dasd_eckd_build_cp_cmd_single(startdev, block, req,
						    first_rec, last_rec,
						    first_trk, last_trk,
						    first_offs, last_offs,
						    blk_per_trk, blksize);

	if (!IS_ERR(cqr)) {
		cqr->start_trk = first_trk;
		cqr->end_trk = last_trk;
	}
	return cqr;
}

static struct dasd_ccw_req *dasd_eckd_build_cp_raw(struct dasd_device *startdev,
						   struct dasd_block *block,
						   struct request *req)
{
	sector_t start_padding_sectors, end_sector_offset, end_padding_sectors;
	unsigned int seg_len, len_to_track_end;
	unsigned int cidaw, cplength, datasize;
	sector_t first_trk, last_trk, sectors;
	struct dasd_eckd_private *base_priv;
	struct dasd_device *basedev;
	struct req_iterator iter;
	struct dasd_ccw_req *cqr;
	unsigned int trkcount;
	unsigned int size;
	unsigned char cmd;
	struct bio_vec bv;
	struct ccw1 *ccw;
	dma64_t *idaws;
	int use_prefix;
	void *data;
	char *dst;

	/*
	 * raw track access needs to be multiple of 64k and on 64k boundary
	 * For read requests we can fix an incorrect alignment by padding
	 * the request with dummy pages.
	 */
	start_padding_sectors = blk_rq_pos(req) % DASD_RAW_SECTORS_PER_TRACK;
	end_sector_offset = (blk_rq_pos(req) + blk_rq_sectors(req)) %
		DASD_RAW_SECTORS_PER_TRACK;
	end_padding_sectors = (DASD_RAW_SECTORS_PER_TRACK - end_sector_offset) %
		DASD_RAW_SECTORS_PER_TRACK;
	basedev = block->base;
	if ((start_padding_sectors || end_padding_sectors) &&
	    (rq_data_dir(req) == WRITE)) {
		DBF_DEV_EVENT(DBF_ERR, basedev,
			      "raw write not track aligned (%llu,%llu) req %p",
			      start_padding_sectors, end_padding_sectors, req);
		return ERR_PTR(-EINVAL);
	}

	first_trk = blk_rq_pos(req) / DASD_RAW_SECTORS_PER_TRACK;
	last_trk = (blk_rq_pos(req) + blk_rq_sectors(req) - 1) /
		DASD_RAW_SECTORS_PER_TRACK;
	trkcount = last_trk - first_trk + 1;

	if (rq_data_dir(req) == READ)
		cmd = DASD_ECKD_CCW_READ_TRACK;
	else if (rq_data_dir(req) == WRITE)
		cmd = DASD_ECKD_CCW_WRITE_FULL_TRACK;
	else
		return ERR_PTR(-EINVAL);

	/*
	 * Raw track based I/O needs IDAWs for each page,
	 * and not just for 64 bit addresses.
	 */
	cidaw = trkcount * DASD_RAW_BLOCK_PER_TRACK;

	/*
	 * struct PFX_eckd_data and struct LRE_eckd_data can have up to 2 bytes
	 * of extended parameter. This is needed for write full track.
	 */
	base_priv = basedev->private;
	use_prefix = base_priv->features.feature[8] & 0x01;
	if (use_prefix) {
		cplength = 1 + trkcount;
		size = sizeof(struct PFX_eckd_data) + 2;
	} else {
		cplength = 2 + trkcount;
		size = sizeof(struct DE_eckd_data) +
			sizeof(struct LRE_eckd_data) + 2;
	}
	size = ALIGN(size, 8);

	datasize = size + cidaw * sizeof(unsigned long);

	/* Allocate the ccw request. */
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength,
				   datasize, startdev, blk_mq_rq_to_pdu(req));
	if (IS_ERR(cqr))
		return cqr;

	ccw = cqr->cpaddr;
	data = cqr->data;

	if (use_prefix) {
		prefix_LRE(ccw++, data, first_trk, last_trk, cmd, basedev,
			   startdev, 1, 0, trkcount, 0, 0);
	} else {
		define_extent(ccw++, data, first_trk, last_trk, cmd, basedev, 0);
		ccw[-1].flags |= CCW_FLAG_CC;

		data += sizeof(struct DE_eckd_data);
		locate_record_ext(ccw++, data, first_trk, 0,
				  trkcount, cmd, basedev, 0, 0);
	}

	idaws = (dma64_t *)(cqr->data + size);
	len_to_track_end = 0;
	if (start_padding_sectors) {
		ccw[-1].flags |= CCW_FLAG_CC;
		ccw->cmd_code = cmd;
		/* maximum 3390 track size */
		ccw->count = 57326;
		/* 64k map to one track */
		len_to_track_end = 65536 - start_padding_sectors * 512;
		ccw->cda = virt_to_dma32(idaws);
		ccw->flags |= CCW_FLAG_IDA;
		ccw->flags |= CCW_FLAG_SLI;
		ccw++;
		for (sectors = 0; sectors < start_padding_sectors; sectors += 8)
			idaws = idal_create_words(idaws, rawpadpage, PAGE_SIZE);
	}
	rq_for_each_segment(bv, req, iter) {
		dst = bvec_virt(&bv);
		seg_len = bv.bv_len;
		if (cmd == DASD_ECKD_CCW_READ_TRACK)
			memset(dst, 0, seg_len);
		if (!len_to_track_end) {
			ccw[-1].flags |= CCW_FLAG_CC;
			ccw->cmd_code = cmd;
			/* maximum 3390 track size */
			ccw->count = 57326;
			/* 64k map to one track */
			len_to_track_end = 65536;
			ccw->cda = virt_to_dma32(idaws);
			ccw->flags |= CCW_FLAG_IDA;
			ccw->flags |= CCW_FLAG_SLI;
			ccw++;
		}
		len_to_track_end -= seg_len;
		idaws = idal_create_words(idaws, dst, seg_len);
	}
	for (sectors = 0; sectors < end_padding_sectors; sectors += 8)
		idaws = idal_create_words(idaws, rawpadpage, PAGE_SIZE);
	if (blk_noretry_request(req) ||
	    block->base->features & DASD_FEATURE_FAILFAST)
		set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->startdev = startdev;
	cqr->memdev = startdev;
	cqr->block = block;
	cqr->expires = startdev->default_expires * HZ;
	cqr->lpm = dasd_path_get_ppm(startdev);
	cqr->retries = startdev->default_retries;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	return cqr;
}


static int
dasd_eckd_free_cp(struct dasd_ccw_req *cqr, struct request *req)
{
	struct dasd_eckd_private *private;
	struct ccw1 *ccw;
	struct req_iterator iter;
	struct bio_vec bv;
	char *dst, *cda;
	unsigned int blksize, blk_per_trk, off;
	sector_t recid;
	int status;

	/*
	 * A format-aborted request finished nothing - its replacement
	 * completes the block request - so report ABORTED instead of DONE,
	 * but still release its bounce buffers like any other request.
	 */
	if (cqr->status == DASD_CQR_ABORTED)
		status = DASD_CQR_ABORTED;
	else
		status = cqr->status == DASD_CQR_DONE;
	/* transport mode has no dasd_page_cache bounce buffers to release */
	if (!dasd_page_cache || cqr->cpmode)
		goto out;
	private = cqr->block->base->private;
	blksize = cqr->block->bp_block;
	blk_per_trk = recs_per_track(&private->rdc_data, 0, blksize);
	recid = blk_rq_pos(req) >> cqr->block->s2b_shift;
	ccw = cqr->cpaddr;
	/* Skip over define extent & locate record. */
	ccw++;
	if (private->uses_cdl == 0 || recid > 2*blk_per_trk)
		ccw++;
	rq_for_each_segment(bv, req, iter) {
		dst = bvec_virt(&bv);
		for (off = 0; off < bv.bv_len; off += blksize) {
			/* Skip locate record. */
			if (private->uses_cdl && recid <= 2*blk_per_trk)
				ccw++;
			if (dst) {
				if (ccw->flags & CCW_FLAG_IDA)
					cda = dma64_to_virt(*((dma64_t *)dma32_to_virt(ccw->cda)));
				else
					cda = dma32_to_virt(ccw->cda);
				if (dst != cda) {
					if (rq_data_dir(req) == READ)
						memcpy(dst, cda, bv.bv_len);
					kmem_cache_free(dasd_page_cache,
					    (void *)((addr_t)cda & PAGE_MASK));
				}
				dst = NULL;
			}
			ccw++;
			recid++;
		}
	}
out:
	dasd_sfree_request(cqr, cqr->memdev);
	return status;
}

/*
 * Modify ccw/tcw in cqr so it can be started on a base device.
 *
 * Note that this is not enough to restart the cqr!
 * Either reset cqr->startdev as well (summary unit check handling)
 * or restart via separate cqr (as in ERP handling).
 */
void dasd_eckd_reset_ccw_to_base_io(struct dasd_ccw_req *cqr)
{
	struct ccw1 *ccw;
	struct PFX_eckd_data *pfxdata;
	struct tcw *tcw;
	struct tccb *tccb;
	struct dcw *dcw;

	if (cqr->cpmode == 1) {
		tcw = cqr->cpaddr;
		tccb = tcw_get_tccb(tcw);
		dcw = (struct dcw *)&tccb->tca[0];
		pfxdata = (struct PFX_eckd_data *)&dcw->cd[0];
		pfxdata->validity.verify_base = 0;
		pfxdata->validity.hyper_pav = 0;
	} else {
		ccw = cqr->cpaddr;
		pfxdata = cqr->data;
		if (ccw->cmd_code == DASD_ECKD_CCW_PFX) {
			pfxdata->validity.verify_base = 0;
			pfxdata->validity.hyper_pav = 0;
		}
	}
}

#define DASD_ECKD_CHANQ_MAX_SIZE 4

static struct dasd_ccw_req *dasd_eckd_build_alias_cp(struct dasd_device *base,
						     struct dasd_block *block,
						     struct request *req)
{
	struct dasd_eckd_private *private;
	struct dasd_device *startdev = NULL;
	unsigned long flags;
	struct dasd_ccw_req *cqr;

	/* Discard requests (space release) can only run on the base device. */
	if (req_op(req) != REQ_OP_DISCARD)
		startdev = dasd_alias_get_start_dev(base);
	if (!startdev)
		startdev = base;
	private = startdev->private;
	if (private->count >= DASD_ECKD_CHANQ_MAX_SIZE)
		return ERR_PTR(-EBUSY);

	spin_lock_irqsave(get_ccwdev_lock(startdev->cdev), flags);
	private->count++;
	if ((base->features & DASD_FEATURE_USERAW))
		cqr = dasd_eckd_build_cp_raw(startdev, block, req);
	else
		cqr = dasd_eckd_build_cp(startdev, block, req);
	if (IS_ERR(cqr))
		private->count--;
	spin_unlock_irqrestore(get_ccwdev_lock(startdev->cdev), flags);
	return cqr;
}

static int dasd_eckd_free_alias_cp(struct dasd_ccw_req *cqr,
				   struct request *req)
{
	struct dasd_eckd_private *private;
	unsigned long flags;

	spin_lock_irqsave(get_ccwdev_lock(cqr->memdev->cdev), flags);
	private = cqr->memdev->private;
	private->count--;
	spin_unlock_irqrestore(get_ccwdev_lock(cqr->memdev->cdev), flags);
	if (cqr->format)
		clear_format_track(cqr->format, cqr->block);
	return dasd_eckd_free_cp(cqr, req);
}

static int
dasd_eckd_fill_info(struct dasd_device * device,
		    struct dasd_information2_t * info)
{
	struct dasd_eckd_private *private = device->private;

	info->label_block = 2;
	info->FBA_layout = private->uses_cdl ? 0 : 1;
	info->format = private->uses_cdl ? DASD_FORMAT_CDL : DASD_FORMAT_LDL;
	info->characteristics_size = sizeof(private->rdc_data);
	memcpy(info->characteristics, &private->rdc_data,
	       sizeof(private->rdc_data));
	info->confdata_size = min_t(unsigned long, private->conf.len,
				    sizeof(info->configuration_data));
	memcpy(info->configuration_data, private->conf.data,
	       info->confdata_size);
	return 0;
}

/*
 * SECTION: ioctl functions for eckd devices.
 */

/*
 * Release device ioctl.
 * Buils a channel programm to releases a prior reserved
 * (see dasd_eckd_reserve) device.
 */
static int
dasd_eckd_release(struct dasd_device *device)
__context_unsafe(/* Conditional locking */)
{
	struct dasd_ccw_req *cqr;
	int rc;
	struct ccw1 *ccw;
	int useglobal;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	useglobal = 0;
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
	if (IS_ERR(cqr)) {
		mutex_lock(&dasd_reserve_mutex);
		useglobal = 1;
		cqr = &dasd_reserve_req->cqr;
		memset(cqr, 0, sizeof(*cqr));
		memset(&dasd_reserve_req->ccw, 0,
		       sizeof(dasd_reserve_req->ccw));
		cqr->cpaddr = &dasd_reserve_req->ccw;
		cqr->data = &dasd_reserve_req->data;
		cqr->magic = DASD_ECKD_MAGIC;
	}
	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_RELEASE;
	ccw->flags |= CCW_FLAG_SLI;
	ccw->count = 32;
	ccw->cda = virt_to_dma32(cqr->data);
	cqr->startdev = device;
	cqr->memdev = device;
	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->retries = 2;	/* set retry counter to enable basic ERP */
	cqr->expires = 2 * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	rc = dasd_sleep_on_immediatly(cqr);
	if (!rc)
		clear_bit(DASD_FLAG_IS_RESERVED, &device->flags);

	if (useglobal)
		mutex_unlock(&dasd_reserve_mutex);
	else
		dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/*
 * Reserve device ioctl.
 * Options are set to 'synchronous wait for interrupt' and
 * 'timeout the request'. This leads to a terminate IO if
 * the interrupt is outstanding for a certain time.
 */
static int
dasd_eckd_reserve(struct dasd_device *device)
__context_unsafe(/* Conditional locking */)
{
	struct dasd_ccw_req *cqr;
	int rc;
	struct ccw1 *ccw;
	int useglobal;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	useglobal = 0;
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
	if (IS_ERR(cqr)) {
		mutex_lock(&dasd_reserve_mutex);
		useglobal = 1;
		cqr = &dasd_reserve_req->cqr;
		memset(cqr, 0, sizeof(*cqr));
		memset(&dasd_reserve_req->ccw, 0,
		       sizeof(dasd_reserve_req->ccw));
		cqr->cpaddr = &dasd_reserve_req->ccw;
		cqr->data = &dasd_reserve_req->data;
		cqr->magic = DASD_ECKD_MAGIC;
	}
	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_RESERVE;
	ccw->flags |= CCW_FLAG_SLI;
	ccw->count = 32;
	ccw->cda = virt_to_dma32(cqr->data);
	cqr->startdev = device;
	cqr->memdev = device;
	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->retries = 2;	/* set retry counter to enable basic ERP */
	cqr->expires = 2 * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	rc = dasd_sleep_on_immediatly(cqr);
	if (!rc)
		set_bit(DASD_FLAG_IS_RESERVED, &device->flags);

	if (useglobal)
		mutex_unlock(&dasd_reserve_mutex);
	else
		dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/*
 * Steal lock ioctl - unconditional reserve device.
 * Buils a channel programm to break a device's reservation.
 * (unconditional reserve)
 */
static int
dasd_eckd_steal_lock(struct dasd_device *device)
__context_unsafe(/* Conditional locking */)
{
	struct dasd_ccw_req *cqr;
	int rc;
	struct ccw1 *ccw;
	int useglobal;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	useglobal = 0;
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 32, device, NULL);
	if (IS_ERR(cqr)) {
		mutex_lock(&dasd_reserve_mutex);
		useglobal = 1;
		cqr = &dasd_reserve_req->cqr;
		memset(cqr, 0, sizeof(*cqr));
		memset(&dasd_reserve_req->ccw, 0,
		       sizeof(dasd_reserve_req->ccw));
		cqr->cpaddr = &dasd_reserve_req->ccw;
		cqr->data = &dasd_reserve_req->data;
		cqr->magic = DASD_ECKD_MAGIC;
	}
	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_SLCK;
	ccw->flags |= CCW_FLAG_SLI;
	ccw->count = 32;
	ccw->cda = virt_to_dma32(cqr->data);
	cqr->startdev = device;
	cqr->memdev = device;
	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	cqr->retries = 2;	/* set retry counter to enable basic ERP */
	cqr->expires = 2 * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	rc = dasd_sleep_on_immediatly(cqr);
	if (!rc)
		set_bit(DASD_FLAG_IS_RESERVED, &device->flags);

	if (useglobal)
		mutex_unlock(&dasd_reserve_mutex);
	else
		dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/*
 * SNID - Sense Path Group ID
 * This ioctl may be used in situations where I/O is stalled due to
 * a reserve, so if the normal dasd_smalloc_request fails, we use the
 * preallocated dasd_reserve_req.
 */
static int dasd_eckd_snid(struct dasd_device *device,
			  void __user *argp)
__context_unsafe(/* Conditional locking */)
{
	struct dasd_ccw_req *cqr;
	int rc;
	struct ccw1 *ccw;
	int useglobal;
	struct dasd_snid_ioctl_data usrparm;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
		return -EFAULT;

	useglobal = 0;
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1,
				   sizeof(struct dasd_snid_data), device,
				   NULL);
	if (IS_ERR(cqr)) {
		mutex_lock(&dasd_reserve_mutex);
		useglobal = 1;
		cqr = &dasd_reserve_req->cqr;
		memset(cqr, 0, sizeof(*cqr));
		memset(&dasd_reserve_req->ccw, 0,
		       sizeof(dasd_reserve_req->ccw));
		cqr->cpaddr = &dasd_reserve_req->ccw;
		cqr->data = &dasd_reserve_req->data;
		cqr->magic = DASD_ECKD_MAGIC;
	}
	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_SNID;
	ccw->flags |= CCW_FLAG_SLI;
	ccw->count = 12;
	ccw->cda = virt_to_dma32(cqr->data);
	cqr->startdev = device;
	cqr->memdev = device;
	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
	set_bit(DASD_CQR_ALLOW_SLOCK, &cqr->flags);
	cqr->retries = 5;
	cqr->expires = 10 * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	cqr->lpm = usrparm.path_mask;

	rc = dasd_sleep_on_immediatly(cqr);
	/* verify that I/O processing didn't modify the path mask */
	if (!rc && usrparm.path_mask && (cqr->lpm != usrparm.path_mask))
		rc = -EIO;
	if (!rc) {
		usrparm.data = *((struct dasd_snid_data *)cqr->data);
		if (copy_to_user(argp, &usrparm, sizeof(usrparm)))
			rc = -EFAULT;
	}

	if (useglobal)
		mutex_unlock(&dasd_reserve_mutex);
	else
		dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/*
 * Read performance statistics
 */
static int
dasd_eckd_performance(struct dasd_device *device, void __user *argp)
{
	struct dasd_psf_prssd_data *prssdp;
	struct dasd_rssd_perf_stats_t *stats;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int rc;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */  + 1 /* RSSD */,
				   (sizeof(struct dasd_psf_prssd_data) +
				    sizeof(struct dasd_rssd_perf_stats_t)),
				   device, NULL);
	if (IS_ERR(cqr)) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			    "Could not allocate initialization request");
		return PTR_ERR(cqr);
	}
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->retries = 0;
	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	cqr->expires = 10 * HZ;

	/* Prepare for Read Subsystem Data */
	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
	prssdp->order = PSF_ORDER_PRSSD;
	prssdp->suborder = 0x01;	/* Performance Statistics */
	prssdp->varies[1] = 0x01;	/* Perf Statistics for the Subsystem */

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->count = sizeof(struct dasd_psf_prssd_data);
	ccw->flags |= CCW_FLAG_CC;
	ccw->cda = virt_to_dma32(prssdp);

	/* Read Subsystem Data - Performance Statistics */
	stats = (struct dasd_rssd_perf_stats_t *) (prssdp + 1);
	memset(stats, 0, sizeof(struct dasd_rssd_perf_stats_t));

	ccw++;
	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
	ccw->count = sizeof(struct dasd_rssd_perf_stats_t);
	ccw->cda = virt_to_dma32(stats);

	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	rc = dasd_sleep_on(cqr);
	if (rc == 0) {
		prssdp = (struct dasd_psf_prssd_data *) cqr->data;
		stats = (struct dasd_rssd_perf_stats_t *) (prssdp + 1);
		if (copy_to_user(argp, stats,
				 sizeof(struct dasd_rssd_perf_stats_t)))
			rc = -EFAULT;
	}
	dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/*
 * Get attributes (cache operations)
 * Returnes the cache attributes used in Define Extend (DE).
 */
static int
dasd_eckd_get_attrib(struct dasd_device *device, void __user *argp)
{
	struct dasd_eckd_private *private = device->private;
	struct attrib_data_t attrib = private->attrib;
	int rc;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
	if (!argp)
                return -EINVAL;

	rc = 0;
	if (copy_to_user(argp, (long *) &attrib,
			 sizeof(struct attrib_data_t)))
		rc = -EFAULT;

	return rc;
}

/*
 * Set attributes (cache operations)
 * Stores the attributes for cache operation to be used in Define Extend (DE).
 */
static int
dasd_eckd_set_attrib(struct dasd_device *device, void __user *argp)
{
	struct dasd_eckd_private *private = device->private;
	struct attrib_data_t attrib;

	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;
	if (!argp)
		return -EINVAL;

	if (copy_from_user(&attrib, argp, sizeof(struct attrib_data_t)))
		return -EFAULT;
	private->attrib = attrib;

	dev_info(&device->cdev->dev,
		 "The DASD cache mode was set to %x (%i cylinder prestage)\n",
		 private->attrib.operation, private->attrib.nr_cyl);
	return 0;
}

/*
 * Issue syscall I/O to EMC Symmetrix array.
 * CCWs are PSF and RSSD
 */
static int dasd_symm_io(struct dasd_device *device, void __user *argp)
{
	struct dasd_symmio_parms usrparm;
	char *psf_data, *rssd_result;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	char psf0, psf1;
	int rc;

	if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RAWIO))
		return -EACCES;
	psf0 = psf1 = 0;

	/* Copy parms from caller */
	rc = -EFAULT;
	if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
		goto out;
	/* at least 2 bytes are accessed and should be allocated */
	if (usrparm.psf_data_len < 2) {
		DBF_DEV_EVENT(DBF_WARNING, device,
			      "Symmetrix ioctl invalid data length %d",
			      usrparm.psf_data_len);
		rc = -EINVAL;
		goto out;
	}
	/* alloc I/O data area */
	psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL | GFP_DMA);
	rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL | GFP_DMA);
	if (!psf_data || !rssd_result) {
		rc = -ENOMEM;
		goto out_free;
	}

	/* get syscall header from user space */
	rc = -EFAULT;
	if (copy_from_user(psf_data,
			   (void __user *)(unsigned long) usrparm.psf_data,
			   usrparm.psf_data_len))
		goto out_free;
	psf0 = psf_data[0];
	psf1 = psf_data[1];

	/* setup CCWs for PSF + RSSD */
	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 2, 0, device, NULL);
	if (IS_ERR(cqr)) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			"Could not allocate initialization request");
		rc = PTR_ERR(cqr);
		goto out_free;
	}

	cqr->startdev = device;
	cqr->memdev = device;
	cqr->retries = 3;
	cqr->expires = 10 * HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	/* Build the ccws */
	ccw = cqr->cpaddr;

	/* PSF ccw */
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->count = usrparm.psf_data_len;
	ccw->flags |= CCW_FLAG_CC;
	ccw->cda = virt_to_dma32(psf_data);

	ccw++;

	/* RSSD ccw  */
	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
	ccw->count = usrparm.rssd_result_len;
	ccw->flags = CCW_FLAG_SLI ;
	ccw->cda = virt_to_dma32(rssd_result);

	rc = dasd_sleep_on(cqr);
	if (rc)
		goto out_sfree;

	rc = -EFAULT;
	if (copy_to_user((void __user *)(unsigned long) usrparm.rssd_result,
			   rssd_result, usrparm.rssd_result_len))
		goto out_sfree;
	rc = 0;

out_sfree:
	dasd_sfree_request(cqr, cqr->memdev);
out_free:
	kfree(rssd_result);
	kfree(psf_data);
out:
	DBF_DEV_EVENT(DBF_WARNING, device,
		      "Symmetrix ioctl (0x%02x 0x%02x): rc=%d",
		      (int) psf0, (int) psf1, rc);
	return rc;
}

static int
dasd_eckd_ioctl(struct dasd_block *block, unsigned int cmd, void __user *argp)
{
	struct dasd_device *device = block->base;

	switch (cmd) {
	case BIODASDGATTR:
		return dasd_eckd_get_attrib(device, argp);
	case BIODASDSATTR:
		return dasd_eckd_set_attrib(device, argp);
	case BIODASDPSRD:
		return dasd_eckd_performance(device, argp);
	case BIODASDRLSE:
		return dasd_eckd_release(device);
	case BIODASDRSRV:
		return dasd_eckd_reserve(device);
	case BIODASDSLCK:
		return dasd_eckd_steal_lock(device);
	case BIODASDSNID:
		return dasd_eckd_snid(device, argp);
	case BIODASDSYMMIO:
		return dasd_symm_io(device, argp);
	default:
		return -ENOTTY;
	}
}

/*
 * Dump the range of CCWs into 'page' buffer
 * and return number of printed chars.
 */
static void
dasd_eckd_dump_ccw_range(struct dasd_device *device, struct ccw1 *from,
			 struct ccw1 *to, char *page)
{
	int len, count;
	char *datap;

	len = 0;
	while (from <= to) {
		len += sprintf(page + len, "CCW %px: %08X %08X DAT:",
			       from, ((int *) from)[0], ((int *) from)[1]);

		/* get pointer to data (consider IDALs) */
		if (from->flags & CCW_FLAG_IDA)
			datap = dma64_to_virt(*((dma64_t *)dma32_to_virt(from->cda)));
		else
			datap = dma32_to_virt(from->cda);

		/* dump data (max 128 bytes) */
		for (count = 0; count < from->count && count < 128; count++) {
			if (count % 32 == 0)
				len += sprintf(page + len, "\n");
			if (count % 8 == 0)
				len += sprintf(page + len, " ");
			if (count % 4 == 0)
				len += sprintf(page + len, " ");
			len += sprintf(page + len, "%02x", datap[count]);
		}
		len += sprintf(page + len, "\n");
		from++;
	}
	if (len > 0)
		dev_err(&device->cdev->dev, "%s", page);
}

static void
dasd_eckd_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
			 char *reason)
{
	u64 *sense;
	u64 *stat;

	sense = (u64 *) dasd_get_sense(irb);
	stat = (u64 *) &irb->scsw;
	if (sense) {
		DBF_DEV_EVENT(DBF_EMERG, device, "%s: %016llx %08x : "
			      "%016llx %016llx %016llx %016llx",
			      reason, *stat, *((u32 *) (stat + 1)),
			      sense[0], sense[1], sense[2], sense[3]);
	} else {
		DBF_DEV_EVENT(DBF_EMERG, device, "%s: %016llx %08x : %s",
			      reason, *stat, *((u32 *) (stat + 1)),
			      "NO VALID SENSE");
	}
}

/*
 * Print sense data and related channel program.
 * Parts are printed because printk buffer is only 1024 bytes.
 */
static void dasd_eckd_dump_sense_ccw(struct dasd_device *device,
				 struct dasd_ccw_req *req, struct irb *irb)
{
	struct ccw1 *first, *last, *fail, *from, *to;
	struct device *dev;
	int len, sl, sct;
	char *page;

	dev = &device->cdev->dev;

	page = kzalloc(PAGE_SIZE, GFP_ATOMIC);
	if (page == NULL) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			      "No memory to dump sense data\n");
		return;
	}
	/* dump the sense data */
	len = sprintf(page, "I/O status report:\n");
	len += sprintf(page + len,
		       "in req: %px CC:%02X FC:%02X AC:%02X SC:%02X DS:%02X CS:%02X RC:%d\n",
		       req, scsw_cc(&irb->scsw), scsw_fctl(&irb->scsw),
		       scsw_actl(&irb->scsw), scsw_stctl(&irb->scsw),
		       scsw_dstat(&irb->scsw), scsw_cstat(&irb->scsw),
		       req ? req->intrc : 0);
	len += sprintf(page + len, "Failing CCW: %px\n",
		       dma32_to_virt(irb->scsw.cmd.cpa));
	if (irb->esw.esw0.erw.cons) {
		for (sl = 0; sl < 4; sl++) {
			len += sprintf(page + len, "Sense(hex) %2d-%2d:",
				       (8 * sl), ((8 * sl) + 7));

			for (sct = 0; sct < 8; sct++) {
				len += sprintf(page + len, " %02x",
					       irb->ecw[8 * sl + sct]);
			}
			len += sprintf(page + len, "\n");
		}

		if (irb->ecw[27] & DASD_SENSE_BIT_0) {
			/* 24 Byte Sense Data */
			sprintf(page + len,
				"24 Byte: %x MSG %x, %s MSGb to SYSOP\n",
				irb->ecw[7] >> 4, irb->ecw[7] & 0x0f,
				irb->ecw[1] & 0x10 ? "" : "no");
		} else {
			/* 32 Byte Sense Data */
			sprintf(page + len,
				"32 Byte: Format: %x Exception class %x\n",
				irb->ecw[6] & 0x0f, irb->ecw[22] >> 4);
		}
	} else {
		sprintf(page + len, "SORRY - NO VALID SENSE AVAILABLE\n");
	}
	dev_err(dev, "%s", page);

	if (req) {
		/* req == NULL for unsolicited interrupts */
		/* dump the Channel Program (max 140 Bytes per line) */
		/* Count CCW and print first CCWs (maximum 7) */
		first = req->cpaddr;
		for (last = first; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
		to = min(first + 6, last);
		dev_err(dev, "Related CP in req: %px\n", req);
		dasd_eckd_dump_ccw_range(device, first, to, page);

		/* print failing CCW area (maximum 4) */
		/* scsw->cda is either valid or zero  */
		from = ++to;
		fail = dma32_to_virt(irb->scsw.cmd.cpa); /* failing CCW */
		if (from <  fail - 2) {
			from = fail - 2;     /* there is a gap - print header */
			dev_err(dev, "......\n");
		}
		to = min(fail + 1, last);
		dasd_eckd_dump_ccw_range(device, from, to, page + len);

		/* print last CCWs (maximum 2) */
		len = 0;
		from = max(from, ++to);
		if (from < last - 1) {
			from = last - 1;     /* there is a gap - print header */
			dev_err(dev, "......\n");
		}
		dasd_eckd_dump_ccw_range(device, from, last, page + len);
	}
	kfree(page);
}


/*
 * Print sense data from a tcw.
 */
static void dasd_eckd_dump_sense_tcw(struct dasd_device *device,
				 struct dasd_ccw_req *req, struct irb *irb)
{
	char *page;
	int len, sl, sct, residual;
	struct tsb *tsb;
	u8 *sense, *rcq;

	page = kzalloc(PAGE_SIZE, GFP_ATOMIC);
	if (page == NULL) {
		DBF_DEV_EVENT(DBF_WARNING, device, " %s",
			    "No memory to dump sense data");
		return;
	}
	/* dump the sense data */
	len = sprintf(page, "I/O status report:\n");
	len += sprintf(page + len,
		       "in req: %px CC:%02X FC:%02X AC:%02X SC:%02X DS:%02X "
		       "CS:%02X fcxs:%02X schxs:%02X RC:%d\n",
		       req, scsw_cc(&irb->scsw), scsw_fctl(&irb->scsw),
		       scsw_actl(&irb->scsw), scsw_stctl(&irb->scsw),
		       scsw_dstat(&irb->scsw), scsw_cstat(&irb->scsw),
		       irb->scsw.tm.fcxs,
		       (irb->scsw.tm.ifob << 7) | irb->scsw.tm.sesq,
		       req ? req->intrc : 0);
	len += sprintf(page + len, "Failing TCW: %px\n",
		       dma32_to_virt(irb->scsw.tm.tcw));

	tsb = NULL;
	sense = NULL;
	if (irb->scsw.tm.tcw && (irb->scsw.tm.fcxs & 0x01))
		tsb = tcw_get_tsb(dma32_to_virt(irb->scsw.tm.tcw));

	if (tsb) {
		len += sprintf(page + len, "tsb->length %d\n", tsb->length);
		len += sprintf(page + len, "tsb->flags %x\n", tsb->flags);
		len += sprintf(page + len, "tsb->dcw_offset %d\n", tsb->dcw_offset);
		len += sprintf(page + len, "tsb->count %d\n", tsb->count);
		residual = tsb->count - 28;
		len += sprintf(page + len, "residual %d\n", residual);

		switch (tsb->flags & 0x07) {
		case 1:	/* tsa_iostat */
			len += sprintf(page + len, "tsb->tsa.iostat.dev_time %d\n",
				       tsb->tsa.iostat.dev_time);
			len += sprintf(page + len, "tsb->tsa.iostat.def_time %d\n",
				       tsb->tsa.iostat.def_time);
			len += sprintf(page + len, "tsb->tsa.iostat.queue_time %d\n",
				       tsb->tsa.iostat.queue_time);
			len += sprintf(page + len, "tsb->tsa.iostat.dev_busy_time %d\n",
				       tsb->tsa.iostat.dev_busy_time);
			len += sprintf(page + len, "tsb->tsa.iostat.dev_act_time %d\n",
				       tsb->tsa.iostat.dev_act_time);
			sense = tsb->tsa.iostat.sense;
			break;
		case 2: /* ts_ddpc */
			len += sprintf(page + len, "tsb->tsa.ddpc.rc %d\n",
				       tsb->tsa.ddpc.rc);
			for (sl = 0; sl < 2; sl++) {
				len += sprintf(page + len,
					       "tsb->tsa.ddpc.rcq %2d-%2d: ",
					       (8 * sl), ((8 * sl) + 7));
				rcq = tsb->tsa.ddpc.rcq;
				for (sct = 0; sct < 8; sct++) {
					len += sprintf(page + len, "%02x",
						       rcq[8 * sl + sct]);
				}
				len += sprintf(page + len, "\n");
			}
			sense = tsb->tsa.ddpc.sense;
			break;
		case 3: /* tsa_intrg */
			len += sprintf(page + len,
				      "tsb->tsa.intrg.: not supported yet\n");
			break;
		}

		if (sense) {
			for (sl = 0; sl < 4; sl++) {
				len += sprintf(page + len,
					       "Sense(hex) %2d-%2d:",
					       (8 * sl), ((8 * sl) + 7));
				for (sct = 0; sct < 8; sct++) {
					len += sprintf(page + len, " %02x",
						       sense[8 * sl + sct]);
				}
				len += sprintf(page + len, "\n");
			}

			if (sense[27] & DASD_SENSE_BIT_0) {
				/* 24 Byte Sense Data */
				sprintf(page + len,
					"24 Byte: %x MSG %x, %s MSGb to SYSOP\n",
					sense[7] >> 4, sense[7] & 0x0f,
					sense[1] & 0x10 ? "" : "no");
			} else {
				/* 32 Byte Sense Data */
				sprintf(page + len,
					"32 Byte: Format: %x Exception class %x\n",
					sense[6] & 0x0f, sense[22] >> 4);
			}
		} else {
			sprintf(page + len, "SORRY - NO VALID SENSE AVAILABLE\n");
		}
	} else {
		sprintf(page + len, "SORRY - NO TSB DATA AVAILABLE\n");
	}
	dev_err(&device->cdev->dev, "%s", page);
	kfree(page);
}

static void dasd_eckd_dump_sense(struct dasd_device *device,
				 struct dasd_ccw_req *req, struct irb *irb)
{
	u8 *sense = dasd_get_sense(irb);

	/*
	 * In some cases certain errors might be expected and
	 * log messages shouldn't be written then.
	 * Check if the according suppress bit is set.
	 */
	if (sense && (sense[1] & SNS1_INV_TRACK_FORMAT) &&
	    !(sense[2] & SNS2_ENV_DATA_PRESENT) &&
	    test_bit(DASD_CQR_SUPPRESS_IT, &req->flags))
		return;

	if (sense && sense[0] & SNS0_CMD_REJECT &&
	    test_bit(DASD_CQR_SUPPRESS_CR, &req->flags))
		return;

	if (sense && sense[1] & SNS1_NO_REC_FOUND &&
	    test_bit(DASD_CQR_SUPPRESS_NRF, &req->flags))
		return;

	if (scsw_cstat(&irb->scsw) == 0x40 &&
	    test_bit(DASD_CQR_SUPPRESS_IL, &req->flags))
		return;

	if (scsw_is_tm(&irb->scsw))
		dasd_eckd_dump_sense_tcw(device, req, irb);
	else
		dasd_eckd_dump_sense_ccw(device, req, irb);
}

static int dasd_eckd_reload_device(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	char print_uid[DASD_UID_STRLEN];
	int rc, old_base;
	struct dasd_uid uid;
	unsigned long flags;

	/*
	 * remove device from alias handling to prevent new requests
	 * from being scheduled on the wrong alias device
	 */
	dasd_alias_remove_device(device);

	spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
	old_base = private->uid.base_unit_addr;
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);

	/* Read Configuration Data */
	rc = dasd_eckd_read_conf(device);
	if (rc)
		goto out_err;

	dasd_eckd_read_fc_security(device);

	rc = dasd_eckd_generate_uid(device);
	if (rc)
		goto out_err;
	/*
	 * update unit address configuration and
	 * add device to alias management
	 */
	dasd_alias_update_add_device(device);

	dasd_eckd_get_uid(device, &uid);

	if (old_base != uid.base_unit_addr) {
		dasd_eckd_get_uid_string(&private->conf, print_uid);
		dev_info(&device->cdev->dev,
			 "An Alias device was reassigned to a new base device "
			 "with UID: %s\n", print_uid);
	}
	return 0;

out_err:
	return -1;
}

static int dasd_eckd_read_message_buffer(struct dasd_device *device,
					 struct dasd_rssd_messages *messages,
					 __u8 lpum)
{
	struct dasd_rssd_messages *message_buf;
	struct dasd_psf_prssd_data *prssdp;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int rc;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
				   (sizeof(struct dasd_psf_prssd_data) +
				    sizeof(struct dasd_rssd_messages)),
				   device, NULL);
	if (IS_ERR(cqr)) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate read message buffer request");
		return PTR_ERR(cqr);
	}

	cqr->lpm = lpum;
retry:
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->expires = 10 * HZ;
	set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);
	/* dasd_sleep_on_immediatly does not do complex error
	 * recovery so clear erp flag and set retry counter to
	 * do basic erp */
	clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
	cqr->retries = 256;

	/* Prepare for Read Subsystem Data */
	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
	prssdp->order = PSF_ORDER_PRSSD;
	prssdp->suborder = 0x03;	/* Message Buffer */
	/* all other bytes of prssdp must be zero */

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->count = sizeof(struct dasd_psf_prssd_data);
	ccw->flags |= CCW_FLAG_CC;
	ccw->flags |= CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(prssdp);

	/* Read Subsystem Data - message buffer */
	message_buf = (struct dasd_rssd_messages *) (prssdp + 1);
	memset(message_buf, 0, sizeof(struct dasd_rssd_messages));

	ccw++;
	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
	ccw->count = sizeof(struct dasd_rssd_messages);
	ccw->flags |= CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(message_buf);

	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	rc = dasd_sleep_on_immediatly(cqr);
	if (rc == 0) {
		prssdp = (struct dasd_psf_prssd_data *) cqr->data;
		message_buf = (struct dasd_rssd_messages *)
			(prssdp + 1);
		memcpy(messages, message_buf,
		       sizeof(struct dasd_rssd_messages));
	} else if (cqr->lpm) {
		/*
		 * on z/VM we might not be able to do I/O on the requested path
		 * but instead we get the required information on any path
		 * so retry with open path mask
		 */
		cqr->lpm = 0;
		goto retry;
	} else
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
				"Reading messages failed with rc=%d\n"
				, rc);
	dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

static int dasd_eckd_query_host_access(struct dasd_device *device,
				       struct dasd_psf_query_host_access *data)
{
	struct dasd_eckd_private *private = device->private;
	struct dasd_psf_query_host_access *host_access;
	struct dasd_psf_prssd_data *prssdp;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int rc;

	if (!private)
		return -ENODEV;

	/* not available for HYPER PAV alias devices */
	if (!device->block && private->lcu && private->lcu->pav == HYPER_PAV)
		return -EOPNOTSUPP;

	/* may not be supported by the storage server */
	if (!(private->features.feature[14] & 0x80))
		return -EOPNOTSUPP;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
				   sizeof(struct dasd_psf_prssd_data) + 1,
				   device, NULL);
	if (IS_ERR(cqr)) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate read message buffer request");
		return PTR_ERR(cqr);
	}
	host_access = kzalloc_obj(*host_access, GFP_KERNEL | GFP_DMA);
	if (!host_access) {
		dasd_sfree_request(cqr, device);
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate host_access buffer");
		return -ENOMEM;
	}
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 256;
	cqr->expires = 10 * HZ;

	/* Prepare for Read Subsystem Data */
	prssdp = (struct dasd_psf_prssd_data *) cqr->data;
	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
	prssdp->order = PSF_ORDER_PRSSD;
	prssdp->suborder = PSF_SUBORDER_QHA;	/* query host access */
	/* LSS and Volume that will be queried */
	prssdp->lss = READ_ONCE(private->ned_lss);
	prssdp->volume = READ_ONCE(private->ned_ua);
	/* all other bytes of prssdp must be zero */

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->count = sizeof(struct dasd_psf_prssd_data);
	ccw->flags |= CCW_FLAG_CC;
	ccw->flags |= CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(prssdp);

	/* Read Subsystem Data - query host access */
	ccw++;
	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
	ccw->count = sizeof(struct dasd_psf_query_host_access);
	ccw->flags |= CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(host_access);

	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	/* the command might not be supported, suppress error message */
	__set_bit(DASD_CQR_SUPPRESS_CR, &cqr->flags);
	rc = dasd_sleep_on_interruptible(cqr);
	if (rc == 0) {
		*data = *host_access;
	} else {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
				"Reading host access data failed with rc=%d\n",
				rc);
		rc = -EOPNOTSUPP;
	}

	dasd_sfree_request(cqr, cqr->memdev);
	kfree(host_access);
	return rc;
}
/*
 * return number of grouped devices
 */
static int dasd_eckd_host_access_count(struct dasd_device *device)
{
	struct dasd_psf_query_host_access *access;
	struct dasd_ckd_path_group_entry *entry;
	struct dasd_ckd_host_information *info;
	int count = 0;
	int rc, i;

	access = kzalloc_obj(*access, GFP_NOIO);
	if (!access) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate access buffer");
		return -ENOMEM;
	}
	rc = dasd_eckd_query_host_access(device, access);
	if (rc) {
		kfree(access);
		return rc;
	}

	info = (struct dasd_ckd_host_information *)
		access->host_access_information;
	for (i = 0; i < info->entry_count; i++) {
		entry = (struct dasd_ckd_path_group_entry *)
			(info->entry + i * info->entry_size);
		if (entry->status_flags & DASD_ECKD_PG_GROUPED)
			count++;
	}

	kfree(access);
	return count;
}

/*
 * write host access information to a sequential file
 */
static int dasd_hosts_print(struct dasd_device *device, struct seq_file *m)
{
	struct dasd_psf_query_host_access *access;
	struct dasd_ckd_path_group_entry *entry;
	struct dasd_ckd_host_information *info;
	char sysplex[9] = "";
	int rc, i;

	access = kzalloc_obj(*access, GFP_NOIO);
	if (!access) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate access buffer");
		return -ENOMEM;
	}
	rc = dasd_eckd_query_host_access(device, access);
	if (rc) {
		kfree(access);
		return rc;
	}

	info = (struct dasd_ckd_host_information *)
		access->host_access_information;
	for (i = 0; i < info->entry_count; i++) {
		entry = (struct dasd_ckd_path_group_entry *)
			(info->entry + i * info->entry_size);
		/* PGID */
		seq_printf(m, "pgid %*phN\n", 11, entry->pgid);
		/* FLAGS */
		seq_printf(m, "status_flags %02x\n", entry->status_flags);
		/* SYSPLEX NAME */
		memcpy(&sysplex, &entry->sysplex_name, sizeof(sysplex) - 1);
		EBCASC(sysplex, sizeof(sysplex));
		seq_printf(m, "sysplex_name %8s\n", sysplex);
		/* SUPPORTED CYLINDER */
		seq_printf(m, "supported_cylinder %d\n", entry->cylinder);
		/* TIMESTAMP */
		seq_printf(m, "timestamp %lu\n", (unsigned long)
			   entry->timestamp);
	}
	kfree(access);

	return 0;
}

static struct dasd_device
*copy_relation_find_device(struct dasd_copy_relation *copy,
			   char *busid)
{
	int i;

	for (i = 0; i < DASD_CP_ENTRIES; i++) {
		if (copy->entry[i].configured &&
		    strncmp(copy->entry[i].busid, busid, DASD_BUS_ID_SIZE) == 0)
			return copy->entry[i].device;
	}
	return NULL;
}

/*
 * set the new active/primary device
 */
static void copy_pair_set_active(struct dasd_copy_relation *copy, char *new_busid,
				 char *old_busid)
{
	int i;

	for (i = 0; i < DASD_CP_ENTRIES; i++) {
		if (copy->entry[i].configured &&
		    strncmp(copy->entry[i].busid, new_busid,
			    DASD_BUS_ID_SIZE) == 0) {
			copy->active = &copy->entry[i];
			copy->entry[i].primary = true;
		} else if (copy->entry[i].configured &&
			   strncmp(copy->entry[i].busid, old_busid,
				   DASD_BUS_ID_SIZE) == 0) {
			copy->entry[i].primary = false;
		}
	}
}

/*
 * The function will swap the role of a given copy pair.
 * During the swap operation the relation of the blockdevice is disconnected
 * from the old primary and connected to the new.
 *
 * IO is paused on the block queue before swap and may be resumed afterwards.
 */
static int dasd_eckd_copy_pair_swap(struct dasd_device *device, char *prim_busid,
				    char *sec_busid)
{
	struct dasd_eckd_private *prim_priv, *sec_priv;
	struct dasd_device *primary, *secondary;
	struct dasd_copy_relation *copy;
	struct dasd_block *block;
	struct gendisk *gdp;
	int rc;

	copy = device->copy;
	if (!copy)
		return DASD_COPYPAIRSWAP_INVALID;
	primary = copy->active->device;
	if (!primary)
		return DASD_COPYPAIRSWAP_INVALID;
	/* double check if swap has correct primary */
	if (strncmp(dev_name(&primary->cdev->dev), prim_busid, DASD_BUS_ID_SIZE) != 0)
		return DASD_COPYPAIRSWAP_PRIMARY;

	secondary = copy_relation_find_device(copy, sec_busid);
	if (!secondary)
		return DASD_COPYPAIRSWAP_SECONDARY;

	prim_priv = primary->private;
	sec_priv = secondary->private;

	/*
	 * usually the device should be quiesced for swap
	 * for paranoia stop device and requeue requests again
	 */
	dasd_device_set_stop_bits(primary, DASD_STOPPED_PPRC);
	dasd_device_set_stop_bits(secondary, DASD_STOPPED_PPRC);
	dasd_generic_requeue_all_requests(primary);

	/* swap DASD internal device <> block assignment */
	block = primary->block;
	primary->block = NULL;
	secondary->block = block;
	block->base = secondary;
	/* set new primary device in COPY relation */
	copy_pair_set_active(copy, sec_busid, prim_busid);

	/* swap blocklayer device link */
	gdp = block->gdp;
	dasd_add_link_to_gendisk(gdp, secondary);
	rc = device_move(disk_to_dev(gdp), &secondary->cdev->dev, DPM_ORDER_NONE);
	if (rc) {
		dev_err(&primary->cdev->dev,
			"copy_pair_swap: moving blockdevice parent %s->%s failed (%d)\n",
			dev_name(&primary->cdev->dev),
			dev_name(&secondary->cdev->dev), rc);
	}

	if (primary->stopped & DASD_STOPPED_QUIESCE) {
		dasd_device_set_stop_bits(secondary, DASD_STOPPED_QUIESCE);
		dasd_device_remove_stop_bits(primary, DASD_STOPPED_QUIESCE);
	}

	/*
	 * The secondary device never got through format detection, but since it
	 * is a copy of the primary device, the format is exactly the same;
	 * therefore, the detected layout can simply be copied.
	 */
	sec_priv->uses_cdl = prim_priv->uses_cdl;

	/* re-enable device */
	dasd_device_remove_stop_bits(primary, DASD_STOPPED_PPRC);
	dasd_device_remove_stop_bits(secondary, DASD_STOPPED_PPRC);
	dasd_schedule_device_bh(secondary);

	return DASD_COPYPAIRSWAP_SUCCESS;
}

/*
 * Perform Subsystem Function - Peer-to-Peer Remote Copy Extended Query
 */
static int dasd_eckd_query_pprc_status(struct dasd_device *device,
				       struct dasd_pprc_data_sc4 *data)
{
	struct dasd_pprc_data_sc4 *pprc_data;
	struct dasd_psf_prssd_data *prssdp;
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int rc;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */	+ 1 /* RSSD */,
				   sizeof(*prssdp) + sizeof(*pprc_data) + 1,
				   device, NULL);
	if (IS_ERR(cqr)) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate query PPRC status request");
		return PTR_ERR(cqr);
	}
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 256;
	cqr->expires = 10 * HZ;

	/* Prepare for Read Subsystem Data */
	prssdp = (struct dasd_psf_prssd_data *)cqr->data;
	memset(prssdp, 0, sizeof(struct dasd_psf_prssd_data));
	prssdp->order = PSF_ORDER_PRSSD;
	prssdp->suborder = PSF_SUBORDER_PPRCEQ;
	prssdp->varies[0] = PPRCEQ_SCOPE_4;
	pprc_data = (struct dasd_pprc_data_sc4 *)(prssdp + 1);

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->count = sizeof(struct dasd_psf_prssd_data);
	ccw->flags |= CCW_FLAG_CC;
	ccw->flags |= CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(prssdp);

	/* Read Subsystem Data - query host access */
	ccw++;
	ccw->cmd_code = DASD_ECKD_CCW_RSSD;
	ccw->count = sizeof(*pprc_data);
	ccw->flags |= CCW_FLAG_SLI;
	ccw->cda = virt_to_dma32(pprc_data);

	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	rc = dasd_sleep_on_interruptible(cqr);
	if (rc == 0) {
		*data = *pprc_data;
	} else {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
				"PPRC Extended Query failed with rc=%d\n",
				rc);
		rc = -EOPNOTSUPP;
	}

	dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/*
 * ECKD NOP - no operation
 */
static int dasd_eckd_nop(struct dasd_device *device)
{
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int rc;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, 1, device, NULL);
	if (IS_ERR(cqr)) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev, "%s",
				"Could not allocate NOP request");
		return PTR_ERR(cqr);
	}
	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 1;
	cqr->expires = 10 * HZ;

	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_NOP;
	ccw->flags |= CCW_FLAG_SLI;

	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;

	rc = dasd_sleep_on_interruptible(cqr);
	if (rc != 0) {
		DBF_EVENT_DEVID(DBF_WARNING, device->cdev,
				"NOP failed with rc=%d\n", rc);
		rc = -EOPNOTSUPP;
	}
	dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

static int dasd_eckd_device_ping(struct dasd_device *device)
{
	return dasd_eckd_nop(device);
}

/*
 * Perform Subsystem Function - CUIR response
 */
static int
dasd_eckd_psf_cuir_response(struct dasd_device *device, int response,
			    __u32 message_id, __u8 lpum)
{
	struct dasd_psf_cuir_response *psf_cuir;
	int pos = pathmask_to_pos(lpum);
	struct dasd_ccw_req *cqr;
	struct ccw1 *ccw;
	int rc;

	cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1 /* PSF */ ,
				   sizeof(struct dasd_psf_cuir_response),
				   device, NULL);

	if (IS_ERR(cqr)) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			   "Could not allocate PSF-CUIR request");
		return PTR_ERR(cqr);
	}

	psf_cuir = (struct dasd_psf_cuir_response *)cqr->data;
	psf_cuir->order = PSF_ORDER_CUIR_RESPONSE;
	psf_cuir->cc = response;
	psf_cuir->chpid = device->path[pos].chpid;
	psf_cuir->message_id = message_id;
	psf_cuir->cssid = device->path[pos].cssid;
	psf_cuir->ssid = device->path[pos].ssid;
	ccw = cqr->cpaddr;
	ccw->cmd_code = DASD_ECKD_CCW_PSF;
	ccw->cda = virt_to_dma32(psf_cuir);
	ccw->flags = CCW_FLAG_SLI;
	ccw->count = sizeof(struct dasd_psf_cuir_response);

	cqr->startdev = device;
	cqr->memdev = device;
	cqr->block = NULL;
	cqr->retries = 256;
	cqr->expires = 10*HZ;
	cqr->buildclk = get_tod_clock();
	cqr->status = DASD_CQR_FILLED;
	set_bit(DASD_CQR_VERIFY_PATH, &cqr->flags);

	rc = dasd_sleep_on(cqr);

	dasd_sfree_request(cqr, cqr->memdev);
	return rc;
}

/*
 * return configuration data that is referenced by record selector
 * if a record selector is specified or per default return the
 * conf_data pointer for the path specified by lpum
 */
static struct dasd_conf_data *dasd_eckd_get_ref_conf(struct dasd_device *device,
						     __u8 lpum,
						     struct dasd_cuir_message *cuir)
{
	struct dasd_conf_data *conf_data;
	int path, pos;

	if (cuir->record_selector == 0)
		goto out;
	for (path = 0x80, pos = 0; path; path >>= 1, pos++) {
		conf_data = device->path[pos].conf_data;
		if (conf_data->gneq.record_selector ==
		    cuir->record_selector)
			return conf_data;
	}
out:
	return device->path[pathmask_to_pos(lpum)].conf_data;
}

/*
 * This function determines the scope of a reconfiguration request by
 * analysing the path and device selection data provided in the CUIR request.
 * Returns a path mask containing CUIR affected paths for the give device.
 *
 * If the CUIR request does not contain the required information return the
 * path mask of the path the attention message for the CUIR request was reveived
 * on.
 */
static int dasd_eckd_cuir_scope(struct dasd_device *device, __u8 lpum,
				struct dasd_cuir_message *cuir)
{
	struct dasd_conf_data *ref_conf_data;
	unsigned long bitmask = 0, mask = 0;
	struct dasd_conf_data *conf_data;
	unsigned int pos, path;
	char *ref_gneq, *gneq;
	char *ref_ned, *ned;
	int tbcpm = 0;

	/* if CUIR request does not specify the scope use the path
	   the attention message was presented on */
	if (!cuir->ned_map ||
	    !(cuir->neq_map[0] | cuir->neq_map[1] | cuir->neq_map[2]))
		return lpum;

	/* get reference conf data */
	ref_conf_data = dasd_eckd_get_ref_conf(device, lpum, cuir);
	/* reference ned is determined by ned_map field */
	pos = 8 - ffs(cuir->ned_map);
	ref_ned = (char *)&ref_conf_data->neds[pos];
	ref_gneq = (char *)&ref_conf_data->gneq;
	/* transfer 24 bit neq_map to mask */
	mask = cuir->neq_map[2];
	mask |= cuir->neq_map[1] << 8;
	mask |= cuir->neq_map[0] << 16;

	for (path = 0; path < 8; path++) {
		/* initialise data per path */
		bitmask = mask;
		conf_data = device->path[path].conf_data;
		pos = 8 - ffs(cuir->ned_map);
		ned = (char *) &conf_data->neds[pos];
		/* compare reference ned and per path ned */
		if (memcmp(ref_ned, ned, sizeof(*ned)) != 0)
			continue;
		gneq = (char *)&conf_data->gneq;
		/* compare reference gneq and per_path gneq under
		   24 bit mask where mask bit 0 equals byte 7 of
		   the gneq and mask bit 24 equals byte 31 */
		while (bitmask) {
			pos = ffs(bitmask) - 1;
			if (memcmp(&ref_gneq[31 - pos], &gneq[31 - pos], 1)
			    != 0)
				break;
			clear_bit(pos, &bitmask);
		}
		if (bitmask)
			continue;
		/* device and path match the reference values
		   add path to CUIR scope */
		tbcpm |= 0x80 >> path;
	}
	return tbcpm;
}

static void dasd_eckd_cuir_notify_user(struct dasd_device *device,
				       unsigned long paths, int action)
{
	int pos;

	while (paths) {
		/* get position of bit in mask */
		pos = 8 - ffs(paths);
		/* get channel path descriptor from this position */
		if (action == CUIR_QUIESCE)
			pr_warn("Service on the storage server caused path %x.%02x to go offline",
				device->path[pos].cssid,
				device->path[pos].chpid);
		else if (action == CUIR_RESUME)
			pr_info("Path %x.%02x is back online after service on the storage server",
				device->path[pos].cssid,
				device->path[pos].chpid);
		clear_bit(7 - pos, &paths);
	}
}

static int dasd_eckd_cuir_remove_path(struct dasd_device *device, __u8 lpum,
				      struct dasd_cuir_message *cuir)
{
	unsigned long tbcpm;

	tbcpm = dasd_eckd_cuir_scope(device, lpum, cuir);
	/* nothing to do if path is not in use */
	if (!(dasd_path_get_opm(device) & tbcpm))
		return 0;
	if (!(dasd_path_get_opm(device) & ~tbcpm)) {
		/* no path would be left if the CUIR action is taken
		   return error */
		return -EINVAL;
	}
	/* remove device from operational path mask */
	dasd_path_remove_opm(device, tbcpm);
	dasd_path_add_cuirpm(device, tbcpm);
	return tbcpm;
}

/*
 * walk through all devices and build a path mask to quiesce them
 * return an error if the last path to a device would be removed
 *
 * if only part of the devices are quiesced and an error
 * occurs no onlining necessary, the storage server will
 * notify the already set offline devices again
 */
static int dasd_eckd_cuir_quiesce(struct dasd_device *device, __u8 lpum,
				  struct dasd_cuir_message *cuir)
{
	struct dasd_eckd_private *private = device->private;
	struct alias_pav_group *pavgroup, *tempgroup;
	struct dasd_device *dev, *n;
	unsigned long paths = 0;
	unsigned long flags;
	int tbcpm;

	/* active devices */
	list_for_each_entry_safe(dev, n, &private->lcu->active_devices,
				 alias_list) {
		spin_lock_irqsave(get_ccwdev_lock(dev->cdev), flags);
		tbcpm = dasd_eckd_cuir_remove_path(dev, lpum, cuir);
		spin_unlock_irqrestore(get_ccwdev_lock(dev->cdev), flags);
		if (tbcpm < 0)
			goto out_err;
		paths |= tbcpm;
	}
	/* inactive devices */
	list_for_each_entry_safe(dev, n, &private->lcu->inactive_devices,
				 alias_list) {
		spin_lock_irqsave(get_ccwdev_lock(dev->cdev), flags);
		tbcpm = dasd_eckd_cuir_remove_path(dev, lpum, cuir);
		spin_unlock_irqrestore(get_ccwdev_lock(dev->cdev), flags);
		if (tbcpm < 0)
			goto out_err;
		paths |= tbcpm;
	}
	/* devices in PAV groups */
	list_for_each_entry_safe(pavgroup, tempgroup,
				 &private->lcu->grouplist, group) {
		list_for_each_entry_safe(dev, n, &pavgroup->baselist,
					 alias_list) {
			spin_lock_irqsave(get_ccwdev_lock(dev->cdev), flags);
			tbcpm = dasd_eckd_cuir_remove_path(dev, lpum, cuir);
			spin_unlock_irqrestore(
				get_ccwdev_lock(dev->cdev), flags);
			if (tbcpm < 0)
				goto out_err;
			paths |= tbcpm;
		}
		list_for_each_entry_safe(dev, n, &pavgroup->aliaslist,
					 alias_list) {
			spin_lock_irqsave(get_ccwdev_lock(dev->cdev), flags);
			tbcpm = dasd_eckd_cuir_remove_path(dev, lpum, cuir);
			spin_unlock_irqrestore(
				get_ccwdev_lock(dev->cdev), flags);
			if (tbcpm < 0)
				goto out_err;
			paths |= tbcpm;
		}
	}
	/* notify user about all paths affected by CUIR action */
	dasd_eckd_cuir_notify_user(device, paths, CUIR_QUIESCE);
	return 0;
out_err:
	return tbcpm;
}

static int dasd_eckd_cuir_resume(struct dasd_device *device, __u8 lpum,
				 struct dasd_cuir_message *cuir)
{
	struct dasd_eckd_private *private = device->private;
	struct alias_pav_group *pavgroup, *tempgroup;
	struct dasd_device *dev, *n;
	unsigned long paths = 0;
	int tbcpm;

	/*
	 * the path may have been added through a generic path event before
	 * only trigger path verification if the path is not already in use
	 */
	list_for_each_entry_safe(dev, n,
				 &private->lcu->active_devices,
				 alias_list) {
		tbcpm = dasd_eckd_cuir_scope(dev, lpum, cuir);
		paths |= tbcpm;
		if (!(dasd_path_get_opm(dev) & tbcpm)) {
			dasd_path_add_tbvpm(dev, tbcpm);
			dasd_schedule_device_bh(dev);
		}
	}
	list_for_each_entry_safe(dev, n,
				 &private->lcu->inactive_devices,
				 alias_list) {
		tbcpm = dasd_eckd_cuir_scope(dev, lpum, cuir);
		paths |= tbcpm;
		if (!(dasd_path_get_opm(dev) & tbcpm)) {
			dasd_path_add_tbvpm(dev, tbcpm);
			dasd_schedule_device_bh(dev);
		}
	}
	/* devices in PAV groups */
	list_for_each_entry_safe(pavgroup, tempgroup,
				 &private->lcu->grouplist,
				 group) {
		list_for_each_entry_safe(dev, n,
					 &pavgroup->baselist,
					 alias_list) {
			tbcpm = dasd_eckd_cuir_scope(dev, lpum, cuir);
			paths |= tbcpm;
			if (!(dasd_path_get_opm(dev) & tbcpm)) {
				dasd_path_add_tbvpm(dev, tbcpm);
				dasd_schedule_device_bh(dev);
			}
		}
		list_for_each_entry_safe(dev, n,
					 &pavgroup->aliaslist,
					 alias_list) {
			tbcpm = dasd_eckd_cuir_scope(dev, lpum, cuir);
			paths |= tbcpm;
			if (!(dasd_path_get_opm(dev) & tbcpm)) {
				dasd_path_add_tbvpm(dev, tbcpm);
				dasd_schedule_device_bh(dev);
			}
		}
	}
	/* notify user about all paths affected by CUIR action */
	dasd_eckd_cuir_notify_user(device, paths, CUIR_RESUME);
	return 0;
}

static void dasd_eckd_handle_cuir(struct dasd_device *device, void *messages,
				 __u8 lpum)
{
	struct dasd_cuir_message *cuir = messages;
	int response;

	DBF_DEV_EVENT(DBF_WARNING, device,
		      "CUIR request: %016llx %016llx %016llx %08x",
		      ((u64 *)cuir)[0], ((u64 *)cuir)[1], ((u64 *)cuir)[2],
		      ((u32 *)cuir)[3]);

	if (cuir->code == CUIR_QUIESCE) {
		/* quiesce */
		if (dasd_eckd_cuir_quiesce(device, lpum, cuir))
			response = PSF_CUIR_LAST_PATH;
		else
			response = PSF_CUIR_COMPLETED;
	} else if (cuir->code == CUIR_RESUME) {
		/* resume */
		dasd_eckd_cuir_resume(device, lpum, cuir);
		response = PSF_CUIR_COMPLETED;
	} else
		response = PSF_CUIR_NOT_SUPPORTED;

	dasd_eckd_psf_cuir_response(device, response,
				    cuir->message_id, lpum);
	DBF_DEV_EVENT(DBF_WARNING, device,
		      "CUIR response: %d on message ID %08x", response,
		      cuir->message_id);
	/* to make sure there is no attention left schedule work again */
	device->discipline->check_attention(device, lpum);
}

static void dasd_eckd_oos_resume(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;
	struct alias_pav_group *pavgroup, *tempgroup;
	struct dasd_device *dev, *n;
	unsigned long flags;

	spin_lock_irqsave(&private->lcu->lock, flags);
	list_for_each_entry_safe(dev, n, &private->lcu->active_devices,
				 alias_list) {
		if (dev->stopped & DASD_STOPPED_NOSPC)
			dasd_generic_space_avail(dev);
	}
	list_for_each_entry_safe(dev, n, &private->lcu->inactive_devices,
				 alias_list) {
		if (dev->stopped & DASD_STOPPED_NOSPC)
			dasd_generic_space_avail(dev);
	}
	/* devices in PAV groups */
	list_for_each_entry_safe(pavgroup, tempgroup,
				 &private->lcu->grouplist,
				 group) {
		list_for_each_entry_safe(dev, n, &pavgroup->baselist,
					 alias_list) {
			if (dev->stopped & DASD_STOPPED_NOSPC)
				dasd_generic_space_avail(dev);
		}
		list_for_each_entry_safe(dev, n, &pavgroup->aliaslist,
					 alias_list) {
			if (dev->stopped & DASD_STOPPED_NOSPC)
				dasd_generic_space_avail(dev);
		}
	}
	spin_unlock_irqrestore(&private->lcu->lock, flags);
}

static void dasd_eckd_handle_oos(struct dasd_device *device, void *messages,
				 __u8 lpum)
{
	struct dasd_oos_message *oos = messages;

	switch (oos->code) {
	case REPO_WARN:
	case POOL_WARN:
		dev_warn(&device->cdev->dev,
			 "Extent pool usage has reached a critical value\n");
		dasd_eckd_oos_resume(device);
		break;
	case REPO_EXHAUST:
	case POOL_EXHAUST:
		dev_warn(&device->cdev->dev,
			 "Extent pool is exhausted\n");
		break;
	case REPO_RELIEVE:
	case POOL_RELIEVE:
		dev_info(&device->cdev->dev,
			 "Extent pool physical space constraint has been relieved\n");
		break;
	}

	/* In any case, update related data */
	dasd_eckd_read_ext_pool_info(device);

	/* to make sure there is no attention left schedule work again */
	device->discipline->check_attention(device, lpum);
}

static void dasd_eckd_check_attention_work(struct work_struct *work)
{
	struct check_attention_work_data *data;
	struct dasd_rssd_messages *messages;
	struct dasd_device *device;
	int rc;

	data = container_of(work, struct check_attention_work_data, worker);
	device = data->device;
	messages = kzalloc_obj(*messages);
	if (!messages) {
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			      "Could not allocate attention message buffer");
		goto out;
	}
	rc = dasd_eckd_read_message_buffer(device, messages, data->lpum);
	if (rc)
		goto out;

	if (messages->length == ATTENTION_LENGTH_CUIR &&
	    messages->format == ATTENTION_FORMAT_CUIR)
		dasd_eckd_handle_cuir(device, messages, data->lpum);
	if (messages->length == ATTENTION_LENGTH_OOS &&
	    messages->format == ATTENTION_FORMAT_OOS)
		dasd_eckd_handle_oos(device, messages, data->lpum);

out:
	dasd_put_device(device);
	kfree(messages);
	kfree(data);
}

static int dasd_eckd_check_attention(struct dasd_device *device, __u8 lpum)
{
	struct check_attention_work_data *data;

	data = kzalloc_obj(*data, GFP_ATOMIC);
	if (!data)
		return -ENOMEM;
	INIT_WORK(&data->worker, dasd_eckd_check_attention_work);
	dasd_get_device(device);
	data->device = device;
	data->lpum = lpum;
	schedule_work(&data->worker);
	return 0;
}

static int dasd_eckd_disable_hpf_path(struct dasd_device *device, __u8 lpum)
{
	if (~lpum & dasd_path_get_opm(device)) {
		dasd_path_add_nohpfpm(device, lpum);
		dasd_path_remove_opm(device, lpum);
		dev_err(&device->cdev->dev,
			"Channel path %02X lost HPF functionality and is disabled\n",
			lpum);
		return 1;
	}
	return 0;
}

static void dasd_eckd_disable_hpf_device(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	dev_err(&device->cdev->dev,
		"High Performance FICON disabled\n");
	private->fcx_max_data = 0;
}

static int dasd_eckd_hpf_enabled(struct dasd_device *device)
{
	struct dasd_eckd_private *private = device->private;

	if (!private)
		return 0;

	return private->fcx_max_data ? 1 : 0;
}

static void dasd_eckd_handle_hpf_error(struct dasd_device *device,
				       struct irb *irb)
{
	struct dasd_eckd_private *private = device->private;

	if (!private->fcx_max_data) {
		/* sanity check for no HPF, the error makes no sense */
		DBF_DEV_EVENT(DBF_WARNING, device, "%s",
			      "Trying to disable HPF for a non HPF device");
		return;
	}
	if (irb->scsw.tm.sesq == SCSW_SESQ_DEV_NOFCX) {
		dasd_eckd_disable_hpf_device(device);
	} else if (irb->scsw.tm.sesq == SCSW_SESQ_PATH_NOFCX) {
		if (dasd_eckd_disable_hpf_path(device, irb->esw.esw1.lpum))
			return;
		dasd_eckd_disable_hpf_device(device);
		dasd_path_set_tbvpm(device,
				  dasd_path_get_hpfpm(device));
	}
	/*
	 * prevent that any new I/O ist started on the device and schedule a
	 * requeue of existing requests
	 */
	dasd_device_set_stop_bits(device, DASD_STOPPED_NOT_ACC);
	dasd_schedule_requeue(device);
}

static unsigned int dasd_eckd_max_sectors(struct dasd_block *block)
{
	if (block->base->features & DASD_FEATURE_USERAW) {
		/*
		 * the max_blocks value for raw_track access is 256
		 * it is higher than the native ECKD value because we
		 * only need one ccw per track
		 * so the max_hw_sectors are
		 * 2048 x 512B = 1024kB = 16 tracks
		 */
		return DASD_ECKD_MAX_BLOCKS_RAW << block->s2b_shift;
	}

	return DASD_ECKD_MAX_BLOCKS << block->s2b_shift;
}

/*
 * Discard on ECKD releases space through RAS, which works on whole extents.
 * Advertise extent granularity so the block layer only sends extent-aligned
 * discards (avoiding partially specified extents), and only for volumes on ESE
 * hardware. Non-ESE devices are left without discard limits.
 */
static void dasd_eckd_disc_limits(struct dasd_block *block,
				  struct queue_limits *lim)
{
	struct dasd_device *device = block->base;
	struct dasd_eckd_private *private = device->private;
	unsigned int logical_block_size = block->bp_block;
	unsigned int max_discard_sectors, max_bytes, ext_bytes;
	int recs_per_trk, trks_per_cyl, ext_limit, ext_size;

	if (!dasd_eckd_ese_capable(device) || dasd_eckd_ext_size(device) == 0)
		return;

	trks_per_cyl = private->rdc_data.trk_per_cyl;
	recs_per_trk = recs_per_track(&private->rdc_data, 0, logical_block_size);

	ext_size = dasd_eckd_ext_size(device);
	ext_limit = min(private->real_cyl / ext_size, DASD_ECKD_RAS_EXTS_MAX);
	ext_bytes = ext_size * trks_per_cyl * recs_per_trk * logical_block_size;
	if (!ext_bytes)		/* malformed RDC data - leave discard unset */
		return;
	max_bytes = UINT_MAX - (UINT_MAX % ext_bytes);
	if (max_bytes / ext_bytes > ext_limit)
		max_bytes = ext_bytes * ext_limit;

	max_discard_sectors = max_bytes / 512;

	lim->max_hw_discard_sectors = max_discard_sectors;
	/*
	 * ext_bytes is the hardware extent size and is not a power of two, so
	 * the block layer's power-of-two round_up()/round_down() alignment
	 * helpers compute it only approximately. That is a hint, not a
	 * correctness requirement: RAS safety is enforced in the CCW builder,
	 * which rounds the range inward to whole extents and rejects a request
	 * that covers no whole extent, so a misaligned range is never
	 * over-released. At worst a few sub-extent discards are declined.
	 */
	lim->discard_granularity = ext_bytes;
}

static struct ccw_driver dasd_eckd_driver = {
	.driver = {
		.name	= "dasd-eckd",
		.owner	= THIS_MODULE,
		.dev_groups = dasd_dev_groups,
	},
	.ids	     = dasd_eckd_ids,
	.probe	     = dasd_eckd_probe,
	.remove      = dasd_generic_remove,
	.set_offline = dasd_generic_set_offline,
	.set_online  = dasd_eckd_set_online,
	.notify      = dasd_generic_notify,
	.path_event  = dasd_generic_path_event,
	.shutdown    = dasd_generic_shutdown,
	.uc_handler  = dasd_generic_uc_handler,
	.int_class   = IRQIO_DAS,
};

static struct dasd_discipline dasd_eckd_discipline = {
	.owner = THIS_MODULE,
	.name = "ECKD",
	.ebcname = "ECKD",
	.disc_limits = dasd_eckd_disc_limits,
	.check_device = dasd_eckd_check_characteristics,
	.uncheck_device = dasd_eckd_uncheck_device,
	.do_analysis = dasd_eckd_do_analysis,
	.pe_handler = dasd_eckd_pe_handler,
	.basic_to_ready = dasd_eckd_basic_to_ready,
	.online_to_ready = dasd_eckd_online_to_ready,
	.basic_to_known = dasd_eckd_basic_to_known,
	.max_sectors = dasd_eckd_max_sectors,
	.fill_geometry = dasd_eckd_fill_geometry,
	.start_IO = dasd_start_IO,
	.term_IO = dasd_term_IO,
	.handle_terminated_request = dasd_eckd_handle_terminated_request,
	.format_device = dasd_eckd_format_device,
	.check_device_format = dasd_eckd_check_device_format,
	.erp_action = dasd_eckd_erp_action,
	.erp_postaction = dasd_eckd_erp_postaction,
	.check_for_device_change = dasd_eckd_check_for_device_change,
	.build_cp = dasd_eckd_build_alias_cp,
	.free_cp = dasd_eckd_free_alias_cp,
	.dump_sense = dasd_eckd_dump_sense,
	.dump_sense_dbf = dasd_eckd_dump_sense_dbf,
	.fill_info = dasd_eckd_fill_info,
	.ioctl = dasd_eckd_ioctl,
	.reload = dasd_eckd_reload_device,
	.get_uid = dasd_eckd_get_uid,
	.kick_validate = dasd_eckd_kick_validate_server,
	.check_attention = dasd_eckd_check_attention,
	.host_access_count = dasd_eckd_host_access_count,
	.hosts_print = dasd_hosts_print,
	.handle_hpf_error = dasd_eckd_handle_hpf_error,
	.disable_hpf = dasd_eckd_disable_hpf_device,
	.hpf_enabled = dasd_eckd_hpf_enabled,
	.reset_path = dasd_eckd_reset_path,
	.is_ese = dasd_eckd_is_ese,
	.ese_capable = dasd_eckd_ese_capable,
	.on_demand_format = dasd_eckd_on_demand_format,
	.space_allocated = dasd_eckd_space_allocated,
	.space_configured = dasd_eckd_space_configured,
	.logical_capacity = dasd_eckd_logical_capacity,
	.release_space = dasd_eckd_release_space,
	.ext_pool_id = dasd_eckd_ext_pool_id,
	.ext_size = dasd_eckd_ext_size,
	.ext_pool_cap_at_warnlevel = dasd_eckd_ext_pool_cap_at_warnlevel,
	.ext_pool_warn_thrshld = dasd_eckd_ext_pool_warn_thrshld,
	.ext_pool_oos = dasd_eckd_ext_pool_oos,
	.ext_pool_exhaust = dasd_eckd_ext_pool_exhaust,
	.ese_format = dasd_eckd_ese_format,
	.ese_read = dasd_eckd_ese_read,
	.pprc_status = dasd_eckd_query_pprc_status,
	.pprc_enabled = dasd_eckd_pprc_enabled,
	.copy_pair_swap = dasd_eckd_copy_pair_swap,
	.device_ping = dasd_eckd_device_ping,
};

static int __init
dasd_eckd_init(void)
{
	int ret;

	ASCEBC(dasd_eckd_discipline.ebcname, 4);
	dasd_reserve_req = kmalloc_obj(*dasd_reserve_req, GFP_KERNEL | GFP_DMA);
	if (!dasd_reserve_req)
		return -ENOMEM;
	dasd_vol_info_req = kmalloc_obj(*dasd_vol_info_req,
					GFP_KERNEL | GFP_DMA);
	if (!dasd_vol_info_req) {
		kfree(dasd_reserve_req);
		return -ENOMEM;
	}
	pe_handler_worker = kmalloc_obj(*pe_handler_worker,
					GFP_KERNEL | GFP_DMA);
	if (!pe_handler_worker) {
		kfree(dasd_reserve_req);
		kfree(dasd_vol_info_req);
		return -ENOMEM;
	}
	rawpadpage = (void *)__get_free_page(GFP_KERNEL);
	if (!rawpadpage) {
		kfree(pe_handler_worker);
		kfree(dasd_reserve_req);
		kfree(dasd_vol_info_req);
		return -ENOMEM;
	}
	ret = ccw_driver_register(&dasd_eckd_driver);
	if (!ret)
		wait_for_device_probe();
	else {
		kfree(pe_handler_worker);
		kfree(dasd_reserve_req);
		kfree(dasd_vol_info_req);
		free_page((unsigned long)rawpadpage);
	}
	return ret;
}

static void __exit
dasd_eckd_cleanup(void)
{
	ccw_driver_unregister(&dasd_eckd_driver);
	kfree(pe_handler_worker);
	kfree(dasd_reserve_req);
	free_page((unsigned long)rawpadpage);
}

module_init(dasd_eckd_init);
module_exit(dasd_eckd_cleanup);